Let r = rental, g = gas, m = miles r1 + g1 + 0.25m = r2 + g2 + 0.35m now plug in and solve for m 40 + 15 + 0.25m = 45 + 0.35m 55 - 45 = 0.35m - 0.25m 10 = 0.1m 100 = m for 100 miles the cost will be the same now to find the cost 0.25m plug in 100 for m 0.25(100) = 80 for the course of 100 miles the cost will be $80
