It appears that you did not distribute the factor $\displaystyle-{2}{{x}}^{{2}}\usepackage{cmbright}\Huge\$ to all terms in the second function. Start with:

$\displaystyle{\left({f{\cdot}}{g}\right)}{\left({x}\right)}={f{{\left({x}\right)}}}\cdot{g{{\left({x}\right)}}}={\left(-{2}{{x}}^{{2}}\right)}{\left({7}{{x}}^{{2}}-{2}{x}-{5}\right)}\usepackage{cmbright}\Huge\$

Use the distributive property. The correct answer is $\displaystyle-{14}{{x}}^{{4}}+{4}{{x}}^{{3}}+{10}{{x}}^{{2}}\usepackage{cmbright}\Huge\$ .