Answer: [tex]12x+4[/tex]
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:
[tex]perimeter = side 1 + side 2 + side 3[/tex]
Since the question gives us the sides, let's plug it into the equation:
[tex]perimeter = (3x+7) + (4x-9) + (5x+6)[/tex]
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):
[tex]3x + 4x + 5x = 12x[/tex]
Do the same to the other variable:
[tex]7 + (-9) + 6 = 4[/tex]
Put the two variables together:
[tex]12x+4[/tex]
