How many miles were traveled if the trip lasted 5 days and the total expenses were $437.50

A computer research company pays a daily food allowance of $50 plus $0.30 per mile for business trips.

Let C be total cost and d be total distance.

C = 5(50) + .3(d)
437.50 = 5(50) + .3(d)
437.50 = 250 + .3(d)
437.50 - 250 = .3(d)
.3(d) = 187.5
d = 187.5/.3
d = 625


@Squatters, time and speed doesn't matter because the cost per mile is constant no matter how long it takes.

Take away the 5 days part and you've got C = .3d, the 5 days is the y intercept if you think about it.

y = m(x) + b
C = .3(d) + (5 * 50)

It depends on how fast you were traveling, and how long you were driving.