Question 520891: How wide a border of uniform width should be added to a rectangle that is 8 inches by 12 inches to double the area? Answer by solver91311(24713) (Show Source):
Let represent the width of the border. The original rectangle has an area of 8 times 12 = 96, and we want the new area to be twice that, or 192. Since the border goes all the way around, a border of width will add to each dimension. That means:
Multiply the binomials, collect like terms, put the quadratic into standard form, and solve for . Hint: Divide through by 4 before trying to factor the quadratic.
John
My calculator said it, I believe it, that settles it
