Question 100721
These types of problems require you to comprehend the equality. In this case, the rider rides the same distance in each direction. The general distance equation is d = rate * time. We don't know the rate, so let's call it r. Let d stand for the distance traveled. We are told the time in each direction. But going one way the speed was r+5.

{{{5r = d = 4*(r+5)}}}

That simplifies to

{{{5r = 4r + 20}}}

Subtracting 4r from both sides

{{{r = 20}}} and {{{r+5 = 25}}}, which are the speeds outbound and inbound.

ALWAYS check! {{{5*20 = 100 = 4*25}}}. Check.