Solving Head Start Questions for Cars A & B Races

[halbe1]

Homework Statement

Cars A and B are racing each other along the same straight road in the following manner: Car A has a head start and is a distance D_A beyond the starting line at t = 0. The starting line is at x=0. Car A travels at a constant speed v_A. Car B starts at the starting line but has a better engine than Car A, and thus Car B travels at a constant speed v_B, which is greater than v_A.
A)How long after Car B started the race will Car B catch up with Car A?

B)How far from Car B's starting line will the cars be when Car B passes Car A?

Homework Equations

The Attempt at a Solution

 

[harvellt]

what do you have so far?