Respuesta :
For this case we have the following equations:
 y = 60x + 40
 y = 50x + 80
 Equaling both equations we have:
 60x + 40 = 50x + 80
 From here, we clear the value of x:
 60x - 50x = 80 - 40
 10x = 40
 x = 40/10
 x = 4 weeks
 Substituting x = 4 in any of the equations we have:
 y = 60 (4) + 40
 y = 240 + 40
 y = 280 $
 Answer:
 $ 280 4 weeks
 y = 60x + 40
 y = 50x + 80
 Equaling both equations we have:
 60x + 40 = 50x + 80
 From here, we clear the value of x:
 60x - 50x = 80 - 40
 10x = 40
 x = 40/10
 x = 4 weeks
 Substituting x = 4 in any of the equations we have:
 y = 60 (4) + 40
 y = 240 + 40
 y = 280 $
 Answer:
 $ 280 4 weeks