SOLUTION: A gardener has a rectangular flowerbed, 8 m by 6 m. he added a border of uniform width. if the area of the flowerbed was increased by 72m^2, how wide was the border?

Algebra ->  Length-and-distance -> SOLUTION: A gardener has a rectangular flowerbed, 8 m by 6 m. he added a border of uniform width. if the area of the flowerbed was increased by 72m^2, how wide was the border?       Log On


   



Question 799669: A gardener has a rectangular flowerbed, 8 m by 6 m. he added a border of uniform width. if the area of the flowerbed was increased by 72m^2, how wide was the border?

Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
Initial area = 8*6 = 48 sqm
width and length increased by x
length = 8+2x
width = 6+2x
Area = (8+2x)(6+2x)
(8+2x)(6+2x)-48 = 72
48+16x+12x+4x^2-48= 72
4x^2+28x-72=0
/4
x^2+7x-18=0
x^2+9x-2x-18=0
x(x+9)-2(x+9) =0
(x+9)(x-2)=0
x=-9 OR 2
ignore negative
x= 2