two cars start from the same point at the same time and go i

two cars start from the same point at the same time and go in opposite directions. one car averages 30mph and the other car averages 45mph. how long must they travel to be at least 150 miles apart? use the distance formula to solve.

Solution

D=RT
150=30T+45T
150=75T
T=150/75
T=2 HOURS THEY WILL BE 150 MILES APART.
pROOF:
150=30*2+45*2
150=60+90
150=150