-21=x+6+8x

Solution for -21=x+6+8x equation:

Simplifying
-21 = x + 6 + 8x

Reorder the terms:
-21 = 6 + x + 8x

Combine like terms: x + 8x = 9x
-21 = 6 + 9x

Solving
-21 = 6 + 9x

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '-9x' to each side of the equation.
-21 + -9x = 6 + 9x + -9x

Combine like terms: 9x + -9x = 0
-21 + -9x = 6 + 0
-21 + -9x = 6

Add '21' to each side of the equation.
-21 + 21 + -9x = 6 + 21

Combine like terms: -21 + 21 = 0
0 + -9x = 6 + 21
-9x = 6 + 21

Combine like terms: 6 + 21 = 27
-9x = 27

Divide each side by '-9'.
x = -3

Simplifying
x = -3