a/ \(y=\left(2x+1\right)\left(x-2\right)\left(3-x\right)=-2x^3+9x^2-7x-6\)
\(\Rightarrow y'=-6x^2+18x-7\)
b/ \(y=\left(2x^2+1\right)\left(x^2+x+2\right)x=\left(2x^2+1\right)\left(x^3+x^2+2x\right)\)
\(y'=4x\left(x^3+x^2+2x\right)+\left(2x^2+1\right)\left(3x^2+2x+2\right)\)