The length of a rectangle is cm more than its width. Given that its area is , determine its perimeter.
Denote the length of the rectangle by and the width of the rectangle by . If the length is cm more than the width, then
If the area of the rectangle is cm, then
This pair of equations can be solved by substitution. Substituting the first order equation into the second order equation gives
This equation can be solved by factorisation.
As represents the width of a rectangle, it must have a positive value. Therefore, cm.
Now substitute this value of into the first order equation to find .
The perimeter of the rectangle is therefore