Answer
$\frac{dA}{dt}=9\sqrt t+\frac{5}{2\sqrt t}$
Work Step by Step
$A=l \times h$
$A=(6t+5)(\sqrt t)$
$A=6t^{\frac{3}{2}}+5t^{\frac{1}{2}}$
$\frac{dA}{dt}=(\frac{3}{2})6t^{\frac{1}{2}}+(\frac{1}{2})5t^{-\frac{1}{2}}$
$\frac{dA}{dt}=9\sqrt t+\frac{5}{2\sqrt t}$
