CPM Homework Help : AC Problem 4-105

When Ellen started with Regina's favorite number and tripled it, the result was twelve more than twice the favorite number. Define a variable, write an equation, and then use the equation to find Regina's favorite number.

Hint 1:

Define a variable.

$r$ = Regina's favorite number

Hint 2:

Use the first sentence to write an equation.

Hint 3:

Look at the important parts of the problem above.

$\color{blue}{3r} \color{purple}{=} \color{orange}{12} + \color{green}{2r}$

Solve for $r$ .