Linear System Speed question

A traffic helicopter pilot finds that with a tailwind her 120km trip away from the airport takes 30 minutes. on her trip to the airport, into the wind, she finds that her trip is 10 minutes longer. What is the speed of the helicopter? what is the speed of the wind?

COULD YOU PLEASE CLARIFY WHAT YOU DO STEP BY STEP BECAUSE I WANT TO KNOW HOW TO SOLVE THESE TYPES OF QUESTIONS
I WOULD HIGHLY APPRECIATE IT!
thank you

distance = speed x time
let x be speed of plane with no wind, w = wind speed

on leg 1, speed = 120 km / 30 min = 4 km/min = x+w
on leg 2, speed = 120 / 40 = 3 km/min = x–w

x+w = 4
x–w = 3
add
2x = 7
x = 3.5 km/min
w = 4–x = 0.5 km/min