Answer: 0.35M + 5.45
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Work Shown:
M = number of miles
L = cost to rent a luxury car = 1.15M + 16.40
E = cost to rent an economy car = 0.80M+10.95
C = difference in price
C = L - E
C = (1.15M + 16.40) - (0.80M+10.95)
C = 1.15M + 16.40 - 0.80M-10.95
C = 0.35M + 5.45
Don't forget to distribute the negative to each term in the second parenthesis.
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Optional Section:
Let's say you drove M = 100 miles as an example.
The luxury car would cost L = 1.15M+16.40 = 1.15*100+16.40 = 131.40 dollars to rent.
The economy car would cost E = 0.80M+10.95 = 0.80*100+10.95 = 90.95 dollars to rent.
The difference in rental costs is L-E = 131.40-90.95 = 40.45 dollars.
Or you could say C = 0.35M+5.45 = 0.35*100+5.45 = 40.45
This means you pay $40.45 more if you go for a luxury car instead of an economy car.