Ok I think it means that the length [tex]l[/tex] of the rectangle is 2 m more than is width [tex]w[/tex]...
The area is A=[tex]l*w=(w+2)*w=80[/tex]
so: [tex] w^{2} +2w-80=0[/tex]
Solving this equation (using the quadratic formula) you get 2 solutons. The only acceptable is the positive one, i.e. [tex]w=8 m[/tex], the length will then be [tex]l=w+2=8+2=10m[/tex].