Hi Matthew J.
Perimeter of a Square = 4s where s is the side
Perimeter of a Rectangle = 2L + 2W where L is the length and W is the Width
Since you are given that the Perimeter of the square and the rectangle are equal then
4s = 2L + 2W
Plug in the expressions you are given for the side of the square 6x -2, the length of the rectangle 2x + 2 and the width of the rectangle x + 3 and solve for x
4(6x -2) = 2(2x + 2) + 2(x + 3)
Divide both sides of the equation by 2
2(6x - 2) = 2x + 2 + x + 3
Multiply through the parentheses
12x - 4 = 2x + 2 + x + 3
Combine like terms
12x - 4 = 3x + 5
Isolate the variables on one side of the equation and the constants on the other
12x - 3x = 5 + 4
Combine like terms again
9x = 9
Divide both sides of the equation by 9
x = 1
To check plug this value into both equations for the perimeter of the square and the perimeter of the rectangle
4(6x - 2) = 2(2x + 2) + 2(x + 3)
4(6*1 - 2) = 2( 2*1 + 2) + 2(1 + 3)
4(6 -2) = 2(2 + 2) + 2(4)
4(4) = 2(4) + 2(4)
16 = 8 + 8
16 = 16
I hope this helps.