A triangle has sides measuring 3x + 7, 4x - 9, and 5x + 6. Find the simplified expression that represents the perimeter.

Step-by-step explanation:

We need to add all the sides of the triangle together in order to find the perimeter. The equation to find the perimeter of a triangle is:

Since the question gives us the sides, let's plug it into the equation:

To simplify the equation, first, let's add the x variables together  (remember that we can't add two different variables together, so we can't just add all the numbers together! we have to add the two different variables separately):

Do the same to the other variable:

Put the two variables together:

expression #3 is not equivalent. the others are.

question is incomplete.