Question 442979: solve by the substitution method,whats the solution of system 4x + 5y =13 and -6x +y =57 Found 2 solutions by swincher4391, MathLover1:Answer by swincher4391(1107) (Show Source):
You can put this solution on YOUR website! Notice that with -6x +y =57, y has a coefficient of 1. This will be a good choice for substitution.
Solve for y.
y = 57+6x
Plug 57+6x back in the other equation where you see y.
4x + 5(57+6x) = 13
4x + 285 + 30x = 13
34x = -272
x=-8
Plug -8 back into either equation.
-6(-8) + y = 57
48 + y = 57
y = 9
So our solution is (-8,9) .
Let's check to make sure this works.
4(-8) + 5(9) = -32 + 45 = 13
-6(-8) + 9 = 48 + 9 = 57
So it works.
Hope this helped!
