To multiply a polynomial by a monomial, distribute the monomial to each of the terms in the polynomial. Remember to multiply coefficients and add exponents.

$\displaystyle-{2}{{x}}^{{2}}{\left({3}{{x}}^{{2}}-{2}{x}-{4}\right)}=-{2}{{x}}^{{2}}{\left({3}{{x}}^{{2}}\right)}+{\left(-{2}{{x}}^{{2}}\right)}{\left(-{2}{x}\right)}+{\left(-{2}{{x}}^{{2}}\right)}{\left(-{4}\right)}=-{6}{{x}}^{{4}}+{4}{{x}}^{{3}}+{8}{{x}}^{{2}}\usepackage{cmbright}\Huge\$