Cube root (x+8)-6=-2
If the cube root includes only the (x+8), then add 6 to both sides.
cube root of (x+8) = 4
Now cube both sides to get
x + 8 = 64
x = 58
Check your answer.
cube root of (x+8) = 4
Now cube both sides to get
x + 8 = 64
x = 58
Check your answer.