Matt and Anna are frequent fliers on Fast n Go Airplanes. They often fly between two cities that are a distance of 1680 miles apart. On one particular trip, they flew into the wind and the trip took 4 hours. the return trip with the wind behind them, only took about 3 hours. Find the speed of the wind and the speed of the plane in still air .

The Wind Speed is ____ mph

The Speed of the Plane is ____ mph

Also,

-3x - y = 4
y - 4z = 10
x - 4y + z = -12

What is (X, Y, Z)