What is cross multiplication?

Question

5215 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2014-10-26T21:01:56

We multiply the numerator of each (or one) side by the denominator of the other side.

enter image source here

For example, if I have want to solve for #x# for the following equation:

#x/5=3/4#

I can use cross-multiplication, and the equation becomes:

#x*4=3*5#

#4x=15#

#x=15/4=3.75#