ANSWER
r = -0.8 or 2
Step-by-step explanation
We have the absolute value equation:
3 |3 - 5r| - 3 = 18
First, let us isolate the absolute value:
3 |3 - 5r| = 18 + 3
3 |3 - 5r| = 21
Divide through by 3:
|3 - 5r| = 21 / 3
|3 - 5r| = 7
An aboslute value equation can have two meanings, it could mean that the value in the absolute value function is positive or negative.
That means that we can split the function as follows:
3 - 5r = 7 or 3 - 5r = -7
Collect like terms:
-5r = 7 - 3 or -5r = -7 - 3
-5r = 4 or -5r = -10
Divide through by -5:
r = 4 / -5 or r = -10 / -5
r = -0.8 or 2
That is the value of r.