The expression 4x4x4, x gives the perimeter of a square with a side length of xxx units. what is the perimeter of a square with a side length of \dfrac57 ​7 ​ ​5 ​​ start fraction, 5, divided by, 7, end fraction units?

The expression 4x, gives the perimeter of a square with a side length of x units.
 the perimeter of a square with a side length of x=5/7 is
 4(5/7)=20/7=2.86
 the perimeter of a square is
 2.86