Question 27235
Let the speedd of the plane be x
let the speed of the wind be y
2(x+y)=225 --> solve for y
2x+2y-225
2y=225-2x
y=112.5-x (subsitution)


3h and 45 minutes = 3.75hours.


3.75x-3.75y=225
3.75-3.75(112.5-x)=225
3.75-421.875+3.75=225
7.5x=646.875
x=86.25

y=112.5-86.25
y=26.25


Hence, the speed of the plane is 86/25mph, and the speed of the wind is 26.25mph.
Paul.