Answer:
x = -8
Step-by-step explanation:
-8x + 3(x - 5) = 25
Distribute the 3 into the (x - 5).
-8x + 3x - 15 = 25
Combine like terms.
-5x - 15 = 25
Add 15 to both sides.
-5x = 40
Divide both sides by -5.
x = -8.
Proof:
-8x + 3(x - 5) = 25
Substitute variable.
-8(-8) + 3((-8) - 5) = 25
Subtract inside parenthesis.
-8(-8) + 3(-13) = 25
Multiply -8 and -8.
64 + 3(-13) = 25
Multiply 3 and -13.
64 + (-39) = 25
Add 64 and -39.
25 = 25