Raul is solving -6x=72.find his mistake and correct it.

I don't see any errors. Raul has the correct steps and final answer. We can check the answer by replacing x with -12 and simplifying the left side

-6x = 72
-6*x = 72
-6*(-12) = 72 ... replace x with -12
72 = 72 

Since we get a true equation, we have confirmed the answer is actually x = -12