You can
put this solution on YOUR website!Let x=width of the rectangle
2x+2=length of the rectangle
If Area=length x width

2x+12=0 and x-5=0
2x+12-12=0-12
2x=-12
x=-6, but the width cannot be negative
x-5=0
x-5+5=0+5
x=5, width is 5km
2(5)+2=12km
The length of the rectangle is 12km