Question 904219
400=(x+x+20)
80=2x+20
60=2x
x=30 mph
x+20=50 mph
check
d=r*t+R*t
400=50*t+30*t
400=80*t
t=5 hours
d=R*t
d=30*5
d=150 miles at 30 mph
d=r*t
d=50*5
d=250 miles at 50 mph