SOLUTION: find the dimensions of a rectangle if the area is 4cm and the perimeter is 14cm

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Question 307660:

find the dimensions of a rectangle if the area is 4cm and the perimeter is 14cm
Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
XY=4 OR X=4/Y
2X+2Y=14
2(4/Y)+2Y=14
8/Y+2Y=14
(8+2Y*Y)/Y=14
8+2Y^2=14Y
2Y^2-14Y+8=0
2(Y^2-7Y+4)=0
Y+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
Y=(7+-SQRT[7^2-4*1*4])/2*1
Y=(7+-SQRT[49-16])/2
Y=(7+-SQRT33)/2
Y=(7+5.74)/2
Y=12.74/2
X=6.37 ANS.
X=(7-5.74)/2
Y=1.26/2
Y=.64 ANS.