Question

story prom help in comment

Answer 1

@Directrix

Answer 2

50d + 0.5m = 500
70d - 0.5m = -20
-----------------add
120d = 480
d = 480/120
d = 4

70d - 0.5m = -20
70(4) - 0.5m = -20
280 - 0.5m = -20
-0.5m = -20 - 280
-0.5m = - 300
m = -300/-0.5
m = 600

check...
50d + 0.5m = 500
50(4) + 0.5(600) = 500
200 + 300 = 500
500 = 500 (correct)

70d - 0.5m = -20
70(4) - 0.5(600) = -20
280 - 300 = -20
-20 = -20 (correct)

answer, I believe, is 600 miles and 4 days