Kate has a rectangular garden that is 8 feet long by 3 feet wide. She wishes to extend the length and width by the same amount in order to increase the the area of garden to 104 feet squared. How many feet will she need to add to each side?

Respuesta :

Let the extension of the length and width be x.
 The new dimensions are: Length = 8+x
  Width =3+x
 Area = 104 ft squared
 Area of a rectangle = Length x Width
 Therefore,
(8+x)(3+x) = 104
 x^2 +11x +24=104
 x^2 +11x +24-104=0
 x^2 +11x-80=0

 Factorize using splitting the middle term method. X^2 +16x-5x-80=0 x(x+16)-5(x+16)=0 (x-5)(x+16)=0 either x-5 = 0 or x+16=0 x=5 or x=-16 length and width measure cannot be negative. Therefore, the extension of the length and width is 5 feet each.