F.1 Maths question

As all sides of square are of same length,
x = (2x-3)
x-x = (2x-3)-x
0= x-3
0+3=(x-3)+3
3=x
x=3cm

Perimeter equals to total length of the 4 sides of a square
therefore, 3+3+3+3= 12cm

hope it helps

the solutions:
2x-3=x
2x-x=3
x=3 so the sides is 3 cm each,and the perimeter is 3+3+3+3=12