\(a,\left(-3x^3\right)\left(x^2+5x-\dfrac{1}{3}\right)\)
\(=-3x^5-15x^4+x^3\)
\(b,5p\left(4p^2+7p-3\right)\)
\(=20p^3+35p^2-15p\)
\(c,\left(4y^2-5y+7\right).3y\)
\(=12y^3-15y^2+21y\)
\(d,\left(2x^3-\dfrac{1}{3}x^2+\dfrac{1}{2xy}\right)6x^2y^3\)
\(=12x^5y^3-2x^4y^3+3xy^2\)