A 20 feet piece of string is cut into two pieces so that the longer piece is 5 feet longer than twic

A 20 feet piece of string is cut into two pieces so that the longer piece is 5 feet longer than twice the shorter piece. If the shorter piece is x feet long, find the lengths of both pieces.

If the shorter piece is x, the longer piece is 20 - x

We also are given
20 - x = 2x + 5

Add x to each side:
3x + 5 = 20

Using our equation calculator, we get a shorter piece of:
x = 5

The longer piece is:
20 - x
20 - 5
15