Question 183368
Let W=width and L=length


Since the width is the expression {{{2x-5}}}, this means that {{{W=2x-5}}}


Also, because "the length of the sandbox is designed to be 10 feet longer than the width", this means that {{{L=W+10}}}


{{{L=W+10}}} Start with the second equation



{{{L=2x-5+10}}} Plug in {{{W=2x-5}}}



{{{L=2x+5}}} Combine like terms.




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{{{A=LW}}} Move onto the area of a rectangle formula



{{{A=(2x-5)(2x+5)}}} Plug in {{{W=2x-5}}} and {{{L=2x+5}}}



{{{A=(2x)(2x)+(2x)(5)-5(2x)-5(5)}}} FOIL the expression.



{{{A=4x^2+10x-10x-25}}} Multiply



{{{A=4x^2-25}}} Combine like terms.



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Answer:


So the polynomial that represents the area is {{{A=4x^2-25}}}