In geometry the four sides of a square are all the same length. one side measures (3x+4) and the perimeter of the square is 76. find the value of x.

The perimeter of a square follows the equation P = 4a, in which P is the perimeter and a the length of one side.
We know the perimeter is P = 76, and the length of one side is a = 3x+4.

P = 4a
76 = 4(3x+4)
76 = 12x + 16

We need to solve for x. Let's subtract 16 from both sides to have the variables on a side and the numbers on a side:
76 - 16 = 12x + 16 - 16
60 = 12x

Now, let's divide both sides by 12 to have the variable x on a side and its value on the other
60 = 12x
60/12 = (12x)/12
5 = x

Hope this helps! :D