a plane travels at 336 miles in 2.4 hours against the wind. the return trip takes 2 hours. find the speed of tur plane.

The speed of the plane in still air is 154 mph.

Step-by-step explanation:

speed of plane in still air: v  

speed of wind: a

speed of plane with wind: v + a

speed of planer against the wind: v - a

speed = distance/time

speed of plane against the wind:

v - a = (336 miles)/(2.4 hours)

v - a = 140

speed of plane with wind:

v + a = (336 miles)/(2 hours)

v + a = 168

We have a system of equations:

v - a = 140

v + a = 168

Add the equations to eliminate a:

2v = 308

v = 154

The speed of the plane in still air is 154 mph.

the answer to the question is a  

it has the same slope and the same y-intercept.