Why do you cross multiply?

[greencat217]

The reason we cross multiply fractions is to compare them. Cross multiplying fractions tells us if the two fractions are equal or which one is greater. This is especially useful when you are working with larger fractions that you aren't sure how to reduce.

[heavypanda370]

Cross-multiplication. In mathematics, specifically in elementary arithmetic and elementary algebra, given an equation between two fractions or rational expressions, one can cross-multiply to simplify the equation or determine the value of a variable.

Additionally, can you cross multiply across an equals sign? Multiply both sides by x so that x will be in the numerator. Cancel out the /x * x. Multiply both sides by 3/7 to cancel out the 7/3. Its easier to recognize cross multiplication when the numerators and denominators travel across the equals sign to multiply.

Also, when should you cross multiply?

Cross multiplying is the same thing as multiplying both sides by the least common denominator. If you just remember that to get rid of any fractions, all you have to do is multiply both sides of an equation by the least common denominator, you will never get confused again.

What is the formula of cross multiplication?

Method of Cross Multiplication. The next method of solving linear equations in two variables that we are going to learn about is method of cross multiplication. A2x B2y C2 = 0. The constant terms are: C1 and C2.