Your equation is
7h + 1.50d = Colton's total earnings
We just need to plug in our known numbers for the variables in the equation.
The given numbers are that h=15 and d=8
7(15) + 1.50(8) = Colton's total earnings
Now we just need to simplify this equation by multiplying out the numbers on the left side of the equation.
105 + 12 = Colton's total earnings
Now we add the numbers on the left side of the equation to find Colton's total earnings.
117= Colton's total earnings
Therefore, after working 15 hours and making 8 deliveries, Colton will have earned $117.