The expression 117 = 30 + 3x will aid in solving number 9.
In order to find how far Mr. Glock's car was towed, you need to first subtract 30 from the total amount of money she paid (117).
117 - 30 = 87
Since Mr. Glock is charged $3 per mile to tow the car you need to divide 87 by 3 to find how far the car was towed.
87 ÷ 3 = 29.
Answer: 29 miles