Question

What is the x-coordinate of the point of intersection for these two lines?

9x + 2y = 16
x - 2y = 4
a.) 1
b.) -1
c.) 2
d.) -2

Answer 1

You need to use substitution, to do so, you isolate one of the variables x or y in one equation, and then you substitute that equation into the other.

Since you only need to find x, isolate the y in one of the equations

x - 2y = 4

y =
`(x)/(2) -2`

Plug this in and simplify

9x + 2y = 16

9x + 2(
`(x)/(2) -2`) = 16 Distribute the 2

9x + x - 4 = 16

10x = 20

x = 2 Your answer is C