Word Problems - Linear Equations

Question

A 21 foot board is cut into two pieces, one piece is twice as long as the other. How long are the pieces? Enter both solutions, separated by commas.

Answer 1

Let x be the length of the shorter piece and 2x the longer piece

 

2x + x = 21

3x = 21

x = 7 feet

the longer piece

 2x=2(7)=14 feet

The short piece is 7 feet and the long piece is 14 feet inches.