B In Problems $47-56,$ find the indicated derivatives and simplify.

$47.f^{\text{'}}(x)$ for $f(x)=(2x1)(x^2-3x)$

$48.y^{\text{'}}$ for $y=(x^{3}2x^2)(3x-1)$

$49.\frac{dy}{dt}$ for $y=(2\mathrm{.}5t-t^2)(4t1\mathrm{.}4)$

$50.\frac{d}{dt}[(3-0\mathrm{.}4t^3)(0\mathrm{.}5t^2-2t)]$

$51.y^{\text{'}}$ for $y=\frac{5x-3}{x^{2}2x}$

$52.f^{\text{'}}(x)$ for $f(x)=\frac{3x^2}{2x-1}$

$53.\frac{d}{dw}\frac{w^2-3w1}{w^2-1}$

$54.\frac{dy}{dw}$ for $y=\frac{w^4-w^3}{3w-1}$

$55.y^{\text{'}}$ for $y=(1x-x^2)e^x$

$56.\frac{dy}{dt}$ for $y=(1d^{\text{'}})lnt$