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
<span>Quadratic because you have x^2</span>
Set up a proportion.
10/5=x/7
5x = 70
x = 14
