Respuesta :

Dannymal
x + 10 = -13
-13 - 10 = x
-23 = x

CHECK

-23 + 10 = -13
-13 = -13!
x + 10 = -13 (original problem)
   -10      -10 (subtract 10 from each side)
The 10 - 10 equals 0 so it cancels out of the problem.
x = -23  <- (-13 - 10 = -23)