Help I have the first equation but can’t figure out the second one

Question

A man flies a small airplane from Fargo to Bismarck, North Dakota, a distance of 185 miles. Because he is flying into a head wind, the trip takes him 2.15 hours. On the way back, the wind is still blowing at the same speed, so the return trip takes only 1.38 hours. What is his speed in still air, and how fast is the wind blowing?

Answer 1

d = rt

distance = rate of speed times time traveled

185 = (r - w)2.15

185 = (r+w)1.38

185/2.15 = r-w

185/1.38 = r+w

add two above equations to eliminate one variable

2r = 18t/2.15 + 185/1.38

r = half of (185.215) + 185/1.38) = speed of plane in still air

= about 110.05 mph

w = 185/1.38 - r = 185/1.38 - 110.05 = about 24.01 mph = wind speed