Given the formula d = abc what is the formula for c

Acar started driving from city a to city b, distance between which is 620 miles, at a rate of 60 mph. two hours later a truck left city b and started moving towards city a at a rate of 40 mph. how many hours after the truck's departure will the two meet?

Which statements are true about additional information for proving that the triangles are congruent check all that apply

What is the gcf of 20c^3-5c^4+30c^6