Respuesta :

Answer:

396

Step-by-step explanation:

It's a square.

That means that all four sides are equal.

So the two expressions you have been given are equal.

2.5x + 76.5 = 12x - 9            Subtract 2.5x from both sides.

-2.5x               -2.5x  

          76.5 = 9.5x - 9          Add 9 to both sides

           9                 9

          85.5 = 9.5x              Divide by 9.5

       85.5/9.5 = x

x = 9

That is just the value for x. It is not the answer

Side = 12x - 9

Side = 12*9 - 9

Side = 108 - 9

Side = 99

The perimeter = 4 * Side

The perimeter = 4 * 99

Perimeter = 396