SOLUTION: the area of a rectangular playground in a child care center is 250 square feet. The width of the playground is 20 feet less than twice the length. Fencing must be purchased by the

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Question 442623: the area of a rectangular playground in a child care center is 250 square feet. The width of the playground is 20 feet less than twice the length. Fencing must be purchased by the whole foot and costs $6.95 per foot. Find the cost of fencing purchased to surround the playground.
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
let length be L
width = 2L-20
Area = L * (2L-20)=250
2L^2=20L=250
2L^2-20L-250=0
/2
L^2-10L-125=0
Find the roots of the equation by quadratic formula

a= 1 b= -10 c= -125

b^2-4ac= 100 - 500
b^2-4ac= 600sqrt%28600%29=24.49
x=%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F%282a%29
x1=%28-b%2Bsqrt%28b%5E2-4ac%29%29%2F%282a%29
x1=(10+24.49)/2
x1= 17.25
x2=(10-24.49)/ 2
x2= -7.25
Ignore negative value
Length = 17.25
Width = 2*17.25- 20=14.50
Perimeter = 2*17.25+2*14.50
Perimeter= 34.50+29
Perimeter=63.50 feet
Cost = 63.50*6.95
$441.32