Question 139881
Well, a a square is a rectangle whose sides (length and width) are equal.
So, you have:
L = 2x+1 and W = x+2, so if you set L = W or 2x+2 = x+2 and solve for x, you'll have your answer:
2x+1 = x+2 Subtract x from both sides.
x+1 = 2 Subtract 1 from both sides.
x = 1

Check:
L = 2x+1 Substitute x = 1
L = 2(1)+1
L = 3
W = x+2 Substitute x = 1.
W = 1+2
W = 3
So L = W and you have a square when x = 1.