X+ y = −2
y = 2x + 10

if the two equations are graphed, at what point do the lines representing the two equations intersect?
(−4, 2)
(4, 2)
(−2, 4)
(2, 4)

The first one would be correct!

You can solve simultaneously to find the intersection of the lines. Or use the substitution method,

I used the substitution method where I made X the subject in the first method  so I got X = -2 +y 

use this x to replace it in the second equation 
y= 2(-2 + y ) +10 
therfore y = 2

to find x coordinate, substitute y in any equation to get x = - 4  

so the points of intersection is (-4, 2)

Hope this helped! :) 

It is important because sometimes ur dna needs to multiply