Question 309930
Marcus starts 30 miles from the west coast and drives at 60mph.
 Marcus' grandmother starts 90 miles from the west coast and drives 45mph.
 When will the two of them be the same distance from the west coast?
:
Let t = time when they will be the same distance from the coast
:
Write a distance equation; dist = speed * time
:
Marcus dist from coast = Grandma's distance from coast
60t + 30 = 45t + 90
:
60t - 45t = 90 - 30
:
15t = 60
t = {{{60/15}}}
t = 4 hrs, they will be the same dist from the coast
:
:
Check solution in original equation
60(4) + 30 = 45(4) + 90
240 + 30 = 180 + 90