Respuesta :
Let X = Marinas speed in MPH
Let T = Time
T=288/X
312=(X+6)T
312=(X+6)(288/X)
312=288X/X+1728/X
312=288+1728/X
312-288=1728/X
24=1728/X
24X=1728
X=1728/24
X=72 MPH FOR MARINA
72+6=78 MPH FOR JAMIE
Let X = Marinas speed in MPH
Let T = Time
T=288/X
312=(X+6)T
312=(X+6)(288/X)
312=288X/X+1728/X
312=288+1728/X
312-288=1728/X
24=1728/X
24X=1728
X=1728/24
X=72 MPH FOR MARINA
72+6=78 MPH FOR JAMIE