SOLUTION: The dimensions of a rectangle are 6cm by 8cm. When both dimensions are increased by equal amounts, the area of the rectangle is increased by 208 square cm. Find the dimensions of t

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: The dimensions of a rectangle are 6cm by 8cm. When both dimensions are increased by equal amounts, the area of the rectangle is increased by 208 square cm. Find the dimensions of t      Log On


   



Question 82464: The dimensions of a rectangle are 6cm by 8cm. When both dimensions are increased by equal amounts, the area of the rectangle is increased by 208 square cm. Find the dimensions of the new rectangle.
Answer by checkley75(3666) About Me  (Show Source):
You can put this solution on YOUR website!
(6+X)(8+X)=6*8+208
48+14X+X^2=48+208
X^2+14X-208=0
USING THE QUADRATIC EQUATION WE GET:
X=(-14+-SQRT[14^2-4*1*-208])/2*1
X=(-14+-SQRT[196+832])/2
X=(-14+-SQRT10280/2
X=(-14+-32.06)/2
X=(-14+32.06)/2
X=18.06/2
X=9.03 ANSWER.
PROOF
(6+9.03)(8+9.03)=48+208
15.03*17.03=256
256=256