George and Carmen went on a bicycle trip. they took a bus to their starting point, and then biked the rest. they traveled 200 kilometers in total, and they biked 40 kilometers more than they were bused.
let x= kilometers traveled by bike and y= kilometers traveled by bus.

Respuesta :

x + y = 200
x = y + 40

(y + 40) + y = 200
2y + 40 = 200
2y = 200 - 40
2y = 160
y = 160/2
y = 80

x = y + 40
x = 80 + 40
x = 120

they biked (x) 120 km
they were bused (y) = 80 km