Use addition or substitution to find the value of y for this set of equations. top line 4x + 13y = 40 bottom line 4x + 3y = -40
Using the addition method, you could first multiply one equation by -1
then add to eliminate the x variables.
Let's multiply the second equation by -1 to give us:
4x + 13y = 40
-4x + (-3y) = 40
adding gives us
10y = 80
y = 8 (dividing both sides by 8)
If you also needed to find x, you could then substitute
the value of 8 in for y in one of the equations and solve for x.