What is the answer?

-5x - 10 = 10  x = ?

$\begin{array}{rcll} -5x-10 &=& 10 \qquad | \qquad +10\\ -5x &=& 10 +10\\ -5x &=& 20 \qquad | \qquad \cdot(-1)\\ 5x &=& -20 \\ 5x &=& -20 \qquad | \qquad :5\\ x &=& -\frac{20}{5} \\ x &=& -\frac{4\cdot 5}{5}\\ \mathbf{x} &\mathbf{=}& \mathbf{-4}\\ \end{array}$

-5X-10=10

add ten to both sides

-5x=20

divide both sides by -5

x=-4