Answer:
648mph and 72 mph
Step-by-step explanation:
velocity Against wind=2880/5=576Mph
velocity with the wind =2880/4=720mph
let x be speed of plane y be speed of wind
then velocity with winf=720
x+y=720
velocity against the wind=576
x-y=576
using both
2x=1296
x=648mph
and y=72mph