Suppose $u$ and $v$ are functions of $x$ that are differentiable at $x=0$ and that $u(0)=6,u^{\text{'}}(0)=7,v(0)=9,$ and $v^{\text{'}}(0)=-7.$ Find the values of the following derivatives at $x=0.$

Suppose $u$ and $v$ are functions of $x$ that are differentiable at $x=0$ and that $u(0)=6,u^{\text{'}}(0)=7,v(0)=9,$ and $v^{\text{'}}(0)=-7.$ Find the values of the following derivatives at $x=0.$

a$.\frac{d}{dx}(uv)$

b$.\frac{d}{dx}(\frac{u}{v})$

c$.\frac{d}{dx}(\frac{v}{u})$

d$.\frac{d}{dx}(-9v-4u)$