SOLUTION: A garden 7 m by 12 m will be expanded by planting a border of flowers. The border will be of the same width around the entire garden and has an area of 92 m2. im very confus

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: A garden 7 m by 12 m will be expanded by planting a border of flowers. The border will be of the same width around the entire garden and has an area of 92 m2. im very confus      Log On


   



Question 881994: A garden 7 m by 12 m will be expanded by planting a border of flowers. The border will be of the same width around the entire garden and has an area of 92 m2.

im very confused on this problem. it also needs to be identified if its quadratic equation or not. please do tell if it is.

Answer by rothauserc(4718) About Me  (Show Source):
You can put this solution on YOUR website!
A1 = area of garden including the border (w) = (7+w)*(12+w)
A2 = area of garden = 7 * 12 = 84
Area of border = (7+w)*(12+w) - 84 = 92
(7+w)*(12+w) = 176
w^2 + 19w + 84 = 176
this is a quadratic equation
w^2 + 19w -92 = 0
factor this equation
(w-4) * (w+23) = 0
w is 4 or -23
our answer has to be w > 0, so w = 4 m