The area of a window is 40 square feet. the length is the square root of 20 feet. what is the width of the window

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Given information
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Area = 40ft²
Length = √20 ft

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Formula
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Area = Length x Width

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Find Width
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40 = √20 x width
Width = 40 ÷ √20
Width = 40 ÷ 2√5
Width = 20 ÷ √5

So the first thing we do is to multiply the top equation by 3. the reason i want to do this is i notice there will be a 6y on both equations and can possibly add/subtract them. so we get 6y = -3x + 27. adding that and the second equation we get 6x = 27-15 which is 12. divide by 6 and we get 2. ∴ x = 2. substituting 2 into the first equation we get 2y = -2 + 9 which is 7. divide by 2 and we get 7/2. ∴ y = 7/2, x = 2.