CPM Homework Help : CCA2 Problem 4-85

Three red rods are $2$ cm longer than two blue rods. Three blue rods are $2$ cm longer than four red rods. How long is each rod?

Step 1:

Let $r =$ the length of a red rod and $b =$ the length of a blue rod.
Write and solve a system of equations.

Step 2:

$3r = 2 + 2b$
$3b = 2 + 4r$