3 Ix+3I = Ix-3I+2x
I used the letter (I) and the line for the absolute value. Thanks for your help.
By the way, your keyboard has a key | that is just above the "enter" key. Use that for absolute value.
$\displaystyle 3|x + 3| = |x - 3| + 2x$
There are 3 intervals you need to consider: $\displaystyle (-\infty, -3),~(-3, 3),~(3, \infty)$
On $\displaystyle (-\infty, -3)$ the equation reads
$\displaystyle 3(-x - 3) = -(x - 3) + 2x$
On $\displaystyle (-3, 3)$ the equation reads
$\displaystyle 3(x + 3) = -(x - 3) + 2x$
On $\displaystyle (3, \infty)$ the equation reads
$\displaystyle 3(x + 3) = (x - 3) + 2x$
One, or more, of these equations will give you your solution set.
-Dan