To solve the equation, you can use the following steps:
Start by isolating the absolute value expression on one side of the equation:
-5|x+3| = 18
Now, since the absolute value is positive, it has two solutions:
x + 3 = -18 or x + 3 = 18
Solving for x in each case:
x = -21 (if x + 3 = -18) or x = 15 (if x + 3 = 18)
So the two solutions to the equation are x = -21 and x = 15.