4mm
The sides of the new garden can be represented by x+9. x is the original size and 9 is the added 9mm. Multiply the sides to get (x+9)(x+9) or
this will equal the area. Create an equation to solve for the unknown original length.
Take the square root of both sides
13=x+9
Subtract both sides by 9
4=x The original side was 4mm long
The sides of the new garden can be represented by x+9. x is the original size and 9 is the added 9mm. Multiply the sides to get (x+9)(x+9) or
this will equal the area. Create an equation to solve for the unknown original length.
Take the square root of both sides
13=x+9
Subtract both sides by 9
4=x The original side was 4mm long