Question

what is the y-coordinate of the solution of the system of equations?
3x+2y=-25
-x+y=0

Answer 1

solve the second equation for x. Let me know what you get..

Answer 2

idk....

Answer 3

if you add something to each side of an equation does anything really change, besides the way the equation looks?

Answer 4

no

Answer 5

7x=7 if x=1 then this equation is true, correct?
if we add 3 to each side
7x+3=10 and x is still 1, the equation is still true just looks different

Answer 6

oh okay

Answer 7

we want to get x by itself and positive the easiest way to do that is to add x to each side of the equation.

y - x = 0
y - x + x = 0 + x

Answer 8

y=x
or x=y
doesn't matter how you write it

Answer 9

Now that we know this. we can substitute the x's for a y. This is called the substitution method.

3(y) + 2y = -25

Now solve for y