This is the correct answer: 3x^3 - x^2 + 6x - 9
3 hours.
Explanation
249 total - 84 already paid (for parts) is
165.
165
divided by
55 dollars an hour
is
3 hours worked on repairing.
The answer is either to change the - 1 to 0, or to add + 1 to it next to the - 1.
This is short cut for this type of questions, ie, gain or loss square/100=5^2/100=>0.25%loss
Always this type of questions will have loss
