Arectangular length times its width is 18 square inches what are the possible whole number length and width of the rectangle

It's easy.
the area of the rectangle is 18 sq inches.
It generally means the length and width of the rectangle should be the multiples of 18.

There are 3 possible answers.

lenght=18/width=1 or length=1/width=18
lenght=2/width=9 or length=9/width=2
lenght=6/width=3 or length=3/width=6