Question

-7 - 3x = -13
+7 +7
-------- -------
3x -6
3 3

x = -2

Explanation:

Step1: Add 7 to both sides

$-7 - 3x + 7 = -13 + 7$
$-3x = -6$

Step2: Divide by -3 on both sides

$\frac{-3x}{-3} = \frac{-6}{-3}$

Answer:

$x = 2$

Note: The original work had an error in sign handling after adding 7; the correct intermediate step is $-3x = -6$, leading to a positive solution.