Question

In the following system of equations, what does x equal?
10x + 9y = 3
8x + y = 6

Answer 1

Well you want to in essence "add" these two equations together..

So what you want to do first is get rid of x or y.

We'll get rid of y first. Notice in the top question, y is +9 and in the 2nd, y is 1.

So if we multiply the entire bottom line by -9, our y's will cancel and we can solve for x.