# A triangle has 3 sides 3x+7,4x-9,5x+6. How do you find the expression that represents its perimeter?

Mar 23, 2018

$12 x + 4$

#### Explanation:

The perimeter is the sum of all the lengths of the sides, so we just need to add.
$3 x + 7 + 4 x - 9 + 5 x + 6$
$12 x + 4$

Mar 23, 2018

Let the perimeter be $P$. Then we have:

$P = \left(3 x + 7\right) + \left(4 x - 9\right) + \left(5 x + 6\right) = 12 x + 4$