What is Cross Multiplying?

Hey Vienna! Let’s say you have a math problem where you need to compare two fractions, like this: 1/2 = x/4. This is called a proportion because it shows that two ratios are equal.

To solve for x, we can use a cool trick called cross multiplying. Here’s how it works step-by-step:

1. Draw Your Proportions: Start with the two fractions you want to compare. For example, 1/2 and x/4.
2. Cross Multiply: Imagine an 'X' between the fractions. You take the number from the top left of the first fraction (1) and multiply it by the number at the bottom right of the second fraction (4). That gives you: 1 × 4 = 4.
3. Then Do the Other Side: Now, do the same for the other two numbers: multiply the bottom left number (2) by the top right number (x). That gives you: 2 × x = 2x.
4. Set Up the Equation: Now you have a new equation based on your cross multiplying: 4 = 2x.
5. Solve for x: To find out what x is, you just need to get it all by itself. You can do that by dividing both sides of the equation by 2: 4 ÷ 2 = 2, so x = 2.

And that’s it! You’ve cross-multiplied and found that x = 2!

This method works for any proportions, so now you can try it on other problems too. Happy learning!