8x-21=x

Solution for 8x-21=x equation:

Simplifying
8x + -21 = x

Reorder the terms:
-21 + 8x = x

Solving
-21 + 8x = x

Solving for variable 'x'.

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

Add '-1x' to each side of the equation.
-21 + 8x + -1x = x + -1x

Combine like terms: 8x + -1x = 7x
-21 + 7x = x + -1x

Combine like terms: x + -1x = 0
-21 + 7x = 0

Add '21' to each side of the equation.
-21 + 21 + 7x = 0 + 21

Combine like terms: -21 + 21 = 0
0 + 7x = 0 + 21
7x = 0 + 21

Combine like terms: 0 + 21 = 21
7x = 21

Divide each side by '7'.
x = 3

Simplifying
x = 3