Find area of a rectangle if length is given

AI Thread Summary
The area of a rectangle can be calculated using the formula A = length x width. Given that the length is x and the width is 8 - x, the area can be expressed as A = x(8 - x). Expanding this equation results in A = 8x - x². The discussion highlights confusion regarding the initial problem statement, indicating that additional information may be needed for clarity. Ultimately, the relationship between length, width, and area is confirmed through algebraic expansion.
tayross
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if the length of a rectangle = x,
show that the area of the rectangle is given by A = 8x - x[2]
 
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You need some more information, like that the width of the rectangle is 8 - x.
 


yeah that's what i thought
the answer says

if the length = x then the width equals 1/2 (16 - 2x) = 8 - x

area = length x width

a = x (8 - x )
= 8x - x [2]

do not understand this at all blah!
 


Neither do I, there must be some information you are not giving us.
Please post the entire question.

Other than that, let us assume for a moment that we know that the length of a rectangle is x and its width is 8 - x.
Then do you agree that its area must be x(8 - x)?
Do you see how opening the brackets gives 8x - x2?
 

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