speed of plane in still air ---- x mph
speed of wind ------------ y mph
1575/(x+y) = 7
7x+7y = 1575
x+y = 225
1575(x-y) = 9
9x - 9y = 1575
x - y = 175
add them:
2x = 400
x = 200
back-sub:
200+y = 225
y = 25
state your conclusion
a small plane can fly 1575 miles in 7 hrs in a tailwind. On the return in a headwind, the same trip takes 9 hrs. find the speed in still air (no wind). Then the speed in wind.
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