Answer:
75≤h≤125
Step-by-step explanation:
Let the variable = h
Variable h represents: the number of hours which he must work
If he works for h hours and earns $8 an hour, his income = $8h.
Since he must earn between $600 and 1000 in order to pay for his car insurance, we have the inequality

Next, we solve for h.

Martin must work between 75 to 125 hours in order to be able to pay for his car insurance.