What is the speed of the airplane without a wind?

Question

A pilot flies 512 miles against a 22​-mile-per-hour wind. On the next​ day, the pilot flies back home with a 12​-mile-per-hour tail wind. The total trip​ (both ways) takes 4 hours. Find the speed of the airplane without a wind.

Answer 1

d / r = t

rate_{first day} = r - 22

rate_{second day} = r + 12

time_{first day} = 512 / (r - 22)

time_{second day} = 512 / (r + 12)

512 / (r - 22) + 512 / (r + 12) = 4

Can you solve for r and answer?