Question

two cars start from two towns 400 miles apart and travel towards each other. They pass each other after 4 hours. find the speed of each car if the difference between their speeds is 20 miles per hour.

Answer 1

5 hours

Explanation:

Answer 2

use an expression
s = speed of the slower car
then
(s+20) = speed of the faster car

When they meet is after 400 miles

Write distance equation

slow car d + fast car d = 400 mi
4s + 4(s+20) = 400

8s + 80 = 400

8s = 400 - 80

8s = 320

s = 40 m/H