Question 423020
Solution: Denote x inches the width. Than its length is: x+8 inches.

   Since its area is105 square inches we write the equation:

   x*(x+8)=105 => {{{x^2+8x=105}}} => {{{x^2+8x-105=0}}}

 The final equation is a quadratic equation. Use the quadratic formula to solve it.

        {{{x=(-8+-sqrt(8^2-4*(1)*(-105))/(2*1))}}}

 The root of the equation is x=7.

Answer: the width is 7 inches and the length is 7+8=15 inches.