Find the derivatives with respect to the independent variable t for the following functions using the chain rule: \text { 2.2.1. } f(x(t), t)=\left(4 t^{2}-x\right)\left(t^{3}-8 t^{2}+12\right) \text { 2.2.2. }

f(x(t), t)=\left(1+\sqrt{x^{3}}\right)\left(t^{-3}-2 \sqrt[3]{x}\right) \text { 2.2.3. } f(x(t), t)=(\sqrt{x}+2 x) /\left(7 t-4 x^{2}\right)