## College Algebra 7th Edition

$P(x)=\frac{32}{x}+2x$, $x>0$
We know that the area of the rectangle is: $A=lw=16$ We can solve this for $l$: $l=\frac{16}{w}$ We plug this into the perimeter formula: $P=2l+2w=2(\frac{16}{w})+2w=\frac{32}{w}+2w$ (With $w>0$.) If we use $x$ for $w$, then: $P(x)=\frac{32}{x}+2x$, $x>0$