Answer: x = -3
Explanation:
-x-15-3x=x
subtract x from both sides
-x-15-3x-x=0
Combine -3x and -x to get -4x.
-x-15-4x=0
Add 15 to both sides. Anything plus zero gives itself.
-x-4x=15
Combine -x and -4x to get -5x.
-5x=15
Divide both sides by -5.
x = 15/-5
Divides 15 by -5 to get -3.
x = -3