Question

How to solve x + 2y = 13
4x + 8y = −9
I get confused after eliminating the x.
Please help?

Answer 1

You need to multiply x + 2y = 13 by -4 then the -4 and +4 will cancel each other out then you solve the rest of the equation.

Answer 2

y= zero 

using the process of substitution I had this...

4( -2y +13) +8y = -9
distribution    -8y +52 -8y= -9

so -8y+8y =0 
you end up having zero for y no matter what the subtraction of 52 was, because anything divided by zero is zero...

so if you already have the x value, your point is going to be an x-intercept