SOLUTION: the length of a rectangle is 4 cm greater than its width. the area of the rectangle is 20cm^2. calculate the length and width of the rectangle using algebra.

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Question 362414: the length of a rectangle is 4 cm greater than its width. the area of the rectangle is 20cm^2. calculate the length and width of the rectangle using algebra.
Answer by mananth(16946) About Me  (Show Source):
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the length of a rectangle is 4 cm greater than its width. the area of the rectangle is 20cm^2. calculate the length and width of the rectangle using algebra.
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width be w
length = w+4
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area = L*W
w(w+4)=20
w^2+4w=20
w^2+4w-20=0
factorise by quadratic formula
b^2-4ac= 96
x1=+%28-4%2Bsqrt%2896%29%29%2F2
x1= 2.89cm
x2=+%28-4-sqrt%2896%29%29%2F2
x2=-6.89 Ignore since negative
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width = 2.89 cm
length = 6.89 cm
...
m.ananth@hotmail.ca