Question 380165
Bob's garden -side length be x feet
Area = x*x=x^2
..
Kevin's garden - side length = x+10 feet
..
so area = (x+10)*(x+10)
=x^+20x+100
..
x^2+20x+100=4x^2
3x^2-20x-100=0
3x^2-30x+10x-100=0
3x(x-10)+10(x-10)=0
(x-10)(3x+10)=0
x= 10 
Bob's garden dimensions = 10 feet by 10 feet
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m.ananth@hotmail.ca