Problem
Solve for $u$. \[ \begin{array}{l} -12=4(u-20) \\ u=\square \end{array} \]
Solution
Step 1 ：The equation is in the form of ax = b, where a is the coefficient of the variable, x is the variable and b is the constant. In this case, a = 4, x = u - 20 and b = -12.
Step 2 ：To solve for u, we need to isolate u on one side of the equation. We can do this by first dividing both sides of the equation by 4 to get rid of the coefficient of u.
Step 3 ：Then, we add 20 to both sides to isolate u.
Step 4 ：Doing these steps, we find that the solution to the equation is \(\boxed{17}\).
