maths..

a)The perimeter of a rectangle = 2(4+x) ,So the perimeter of a square = 2(4+x) - 18The length of a side of the square = [2(4+x) - 18]/4= (2x - 10)/4= (x - 5)/2 cmb) The area of a rectangle = 4x while a square = [(x - 5)/2]^24x = [(x - 5)/2]^216x = x^2 - 10x + 25x^2 - 26x + 25 = 0(x - 1)(x - 25) = 0x = 1 (rejected since the side of a square = (1 - 5)/2 = - 2 is impossible) or x = 25