Answer:
9x-3 or 3(3x-1)
Explanation:
A triangle has three sides. To find the perimeter, add those side lengths together.
3x-3+(4x-1)+(2x+1)
Add your common terms (xs and constants) together.
3x+4x+2x=9x
-1+-3+1=-3
9x-3
If you want to, you can factor the expression.
3(3x-1)