Question 624813
There is a pool with a cement walkway around it.  The pool measures 6 meters by 10 meters and the total area of the pool is 96 meters. Find the width of the walkway
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Let w = width of walkway
then
"area of pool & walkway" - "area of pool" = 96
(6+2w)(10+2w) - (6)(10) = 96
60+12w+20w+4w^2 - 60 = 96
60+32w+4w^2 - 60 = 96
32w+4w^2 = 96
4w^2+32w = 96
4w^2+32w-96 = 0
w^2+8w-24 = 0
applying the quadratic formula yields:
w = {-10.32, 2.32}
we can throw out the negative solution leaving:
w = 2.32 meters
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Details of quadratic follows:
*[invoke quadratic "w", 1, 8, -24 ]