y = - 5
substitute the value of x = 4 into the equation and solve for y
- 12 + 9y = - 57 ( add 12 to both sides )
9y = - 45 ( divide both sides by 9 )
y =
= - 5
9w - 7 = 5
9w= 5+7
9w=12
w= 4/3 or 1.33
This can be solved using a system of equations.

Subtract y from both sides.

Substitute:

Subtract 80 from both sides:

Divide both sides by 5:

Substitute.
Answer:
x = 21/4
Step-by-step explanation:
re-arrange the equation
-4+5x-7-3x = 10-2x (move 3x to the other side)
-4+5x-7-3x+2x = 10 (move 2x to the other side)
5x-7-3x+2x = 10+4 (move 4 to the other side)
5x-3x+2x = 10+4+7 (move 7 to the other side)
4x = 21 (add up both sides)
x = 21/4 (divide both sides by 4