Suppose a rectangle has an area of 90m^{2} and the sides are x+1 and x+2. Find the dimensions of the rectangle.
(x+1)·(x+2)=90
x^{2}+3x+2=90
x^{2}+3x-88=0
(x+11)·(x-8)=0
x+11=0; x=-11
x-8=0; x=8
The sides are 9m and 10m long.

An athlete walks 28 km at an unspecified time. If he were to walk 2 km per hour faster he would take 7 hour less to cover the same distance. How long does he spend walking?