SOLUTION: a rectangular lot has a perimeter of 40 meters and an area of 96 sq. meters. what are the dimensions of a lot?

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Question 374315: a rectangular lot has a perimeter of 40 meters and an area of 96 sq. meters. what are the dimensions of a lot?
Answer by checkley79(3341) About Me  (Show Source):
You can put this solution on YOUR website!
XY=96 OR X=90/Y
2X+2Y=40
REPLACING X IN THE SECOND EQUATION WITH (90/Y).
2(90/Y)+2Y=40
180/Y+2Y=40
(180+2Y*Y)/Y=40
(2Y^2+180)/Y=40 CROSS MULTIPLY.
2Y^2+180=40Y
2Y^2-40Y+180=0
2(Y^2-20Y+90)=0
y+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
y=(20+-sqrt[-20^2-4*1*90])/2*1
y=(20+-sqrt[400-360])/2
y=(20+-sqrt40)/2
y=(20+-6.325)/2
y=(20+6.325)/2
y=26.325/2
y=13.1625 ans.
x=90/13.1625
x=6.8376 ans.
Proof:
2*13.625+2*6.8376=40
26.325+13.675=40
40=40