Solve for x -x-1=x-21

$- x - 1 = x - 21$

Step 1

Move all terms containing $x$ to the left side of the equation.

Subtract $x$ from both sides of the equation.

$- x - 1 - x = - 21$

Subtract $x$ from $- x$ .

$- 2 x - 1 = - 21$

Step 2

Move all terms not containing $x$ to the right side of the equation.

Add $1$ to both sides of the equation.

$- 2 x = - 21 + 1$

Add $- 21$ and $1$ .

$- 2 x = - 20$

Step 3

Divide each term in $- 2 x = - 20$ by $- 2$ and simplify.

Divide each term in $- 2 x = - 20$ by $- 2$ .

$\frac{- 2 x}{- 2} = \frac{- 20}{- 2}$

Simplify the left side.

Cancel the common factor of $- 2$ .

Cancel the common factor.

$\frac{- 2 x}{- 2} = \frac{- 20}{- 2}$

Divide $x$ by $1$ .

$x = \frac{- 20}{- 2}$

Simplify the right side.

Divide $- 20$ by $- 2$ .

$x = 10$