Question

The area in square feet of a rectangle field is X squared -100 X +2100. The width, and feet, is X -30. What is the length in feet

Answer 1

Answer: The length is: "(x − 70)" ft.
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Area (A) = Length (L) * width (w) ; that is:

A = L * w ;

We want to solve for the "Length" (L)" ;

So, we can rearrange the equation:

A / w = (L* w) / w ;

to get: A / w = L ;

↔ L = A / w ;

A = (x² − 100x + 2100) ;

w = (x − 30)
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L = (x² − 100x + 2100) / (x − 30) ;
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So; (x − 30) * _?__ = x² − 100x + 2100 ?? ,

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-30 * _?_ = 2100 ? ; → 2100 ÷ (-30) = -70 ;

-30 − 70 = ? -100?? Yes!

So, the answer is: "(x − 70)" ;

That is: " (x − 30) (x − 70) = x² − 100x + 2100 .

The Length is: "(x − 70)" ft.
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