Chapter 5 Polynomials and Polynomial Functions - Standardized Test Practice - Extended Response - Page 411: 20a

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Let $x$ be the height, and let $8-2x$ be the length. The width will be $5-2x$. The volume of the box: $V=x(8-2x)(5-2x)\\=x(4x^2-26x+40)\\=4x^3-26x^2+40x$ Graph the function. The domain is $0\lt x\lt2.5$ The maximum of this function is at $x=1$.