Answer:
Step-by-step explanation:
Let x represent the speed of the slower plane. The faster plane's speed is then x+40. The sum of speeds is ...
x + (x+40) = 1180
2x = 1140 . . . . subtract 40
x = 570 . . . . . .divide by 2
x+40 = 610 . . . . the speed of the faster plane
The two speeds are 570 mph and 610 mph.
