The perimeter of a square is equal to the perimeter of an equilateral triangle. The length of a side of the square is given by x, and the length of a side of the equilateral triangle is given by x + 1. Which equation can be used to find the value of x?
x = 3 (x + 1)
3 x = 4 (x + 1)
4 x = 3 (x + 1)
x = x + 1
