To solve a proportion for a variable you should employ cross multiplication. The basis of cross multiplication is the property which states that the product of the numerator of one fraction and the denominator of what it is set equal to is equal to the product of the remaining denominator and numerator. For example if you have x/15=21/45 you simply need to multiply x by 45 and 15 by 21 then set them equal to each other. The result of this is 45x=315. To solve this new problem for x, divide bo...

Having trouble with long division?? This educational instruction video will teach you how to correctly perform long division. The easy to follow steps will teach you the right technique and you will be able to solve those pesky long division problems in a flash. So if you want to improve your math skills or you just want to learn how to perform long division, watch this easy to follow instructional video that will teach you the simple way of tackling long division problems.

If you've watched our video on solving a Domino Rubik's Cube, you know that asymmetrical Rubik's "Cubes" exist and are readily solvable. If you haven't, go watch that video and come back, because this one is going to teach you how to solve the mother of the domino cube, the 3x3x4 MEGADOMINO (not it's real name). It takes a while and requires some pretty sophisticated Rubik's skills, but if normal Rubik's Cubes are too easy for you go buy one of these!

From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to unpack and solve word problems invplving permutations and combinations in basic stati...

Need to know how to solve algebraic word problems involving age? From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this three-part installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to unpack an...

Need to know how to solve function problems in algebra? From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to work with and solve functions.

This two part video walks you through the steps of solving a strange chess problem. Don't fret, any question you may have, will be answered. Watching this video will make you help you to solve that ever so difficult chess problem.

Check out this instructional math video that demonstrates how to solve ratio problems. In the 14th lesson, learn how to solve SAT problems using the Official SAT Study Guide. Here are the math problems and their page numbers that this video covers:

Check out this instructional math lesson that demonstrates how to solve percentage problems. In the 13th lesson, learn how to solve SAT problems using the Official SAT Study Guide. Here are the math problems and their page numbers that this video covers:

From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to unpack and solve word problems involving a mixture of two or more substances.

From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to work with and solve rate problems in algebra using the distance formula.

Check out this instructional math video that demonstrates how to solve combination and permutation math problems. In the 16th lesson, learn how to solve SAT problems using the Official SAT Study Guide. Here are the math problems and their page numbers that this video covers:

Proportions or ratios are fundamental concepts of mathematics. A proportions is an equation that states that two ratios are equal. Hence proportion can be written in two ways as a:b=c:d or a/b=c/d. In these equations a and d are called as extremes and b,c are called as means. So when working with proportions we can state that product of the means is equal to the product of the extremes i.e. a*d = b*c. This is obtained by cross multiplying the second form of proportions. In mathematics you are...

From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to unpack and solve problems requiring you to add whole numbers.

Check out this instructional math video that demonstrates how to solve number lines. In the 11th lesson, learn how to solve SAT problems using the Official SAT Study Guide. Here are the math problems and their page numbers that this video covers:

This instructional photography video explains how to problem solve small product issues. Two ways to tackle a particular challenge is through pre-production and the other in post-production. There are many different ways a photographer can approach and deal with a challenge. The more knowledge you have about different methodologies about photography, the better and easier you will be able to solve those problems when they occur.

From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to unpack and solve problems requiring you to round whole numbers.

From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to unpack and solve word problems that require you to apply deductive reasoning.

From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to unpack and solve word problems involving events and outcomes.

From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to unpack and solve word problems that require you to simplify rational expressions.

From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to unpack and solve number set problems in intermediate algebra.

See how to unpack and solve a word problem containing radical equations with this free video math lesson from Internet pedagogical superstar Simon Khan. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test).

See how to solve world problems involving the Pythagorean theorem in geometry with this free video math lesson from Internet pedagogical superstar Simon Khan. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test).

See how to find the domain and range of a function implied by a word problem with this free video math lesson. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutor...

Need some help figuring out how to work with angles in geometry? Look no further. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to sol...

Do you need to brush up on your fraction and percentage skills or get ahead of the class in math? This video shows several different examples of how to calculate percentages by using fractions. Money is used as a frequent example because quarters and change are easier to figure out and can help you translate when solving a math problem. You can also solve equations by writing them down and diving the part by the whole. Sound complicated? Watch the video and see how easy you can master calcula...

Many of our members here at Null Byte are aspiring hackers looking to gain skills and credentials to enter the most-valued profession of the 21st century. Hackers are being hired by IT security firms, antivirus developers, national military and espionage organizations, private detectives, and many other organizations.

This video shows the method to solve word problems using proportions. In the given problem, we have to find the time taken by a person to type 390 words if the person takes 1 minute to type 30 words. This can be solved using proportions. We take two fractions which are equal. We type '30 words' in the numerator of the first fraction and 1 minute in its denominator. This fraction must be proportional to the second fraction. The second fraction has '390 words' in the numerator and the variable ...

Want to learn how to solve the Rubik's Cube? Great, well just watch this two-part video tutorial to see how to solve the terrific cubed puzzle without problems. If you're new to the mighty Rubiks Cube puzzle, this will be quite helpful. You just need to know the Rubik's notation, how to turn it and a few simple algorithms. Anyone can solve a Rubik's Cube, really... you're never too old.

See how to apply exponent rules to simplify and solve equations with this free video math lesson from Internet pedagogical superstar Simon Khan. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test).

Need help figuring out how to solve algebra problems involving averages? From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to solve algebr...

From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to solve word problems containing polynomials.

From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps. With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to solve simple percent problems in basic arithmetic.

From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to unpack and solve problems requiring you to compare two or more whole numbers.

From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to solve and work with problems involving inductive reasoning in math.

Many have complained about overheating on the Nikon SB-900 flash. Fortunately this series of videos demonstrates what you can do to prevent this from happening.

From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to find answers to rational equation problems in algebra.

Need help figuring out how to unpack and solve word problems in trig? Learn how with this free video trigonometry lesson. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free...

From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to unpack and solve word problems that require you to divide whole numbers.

Just by moving one match you can turn the math problem into a correct answer. Definitely use this to get some free drinks. And you already know the answer, so it won't be hard. If you want to try and figure this one out for yourself, pause the video before the reveal.