We can use distribution property to multiply the polynomial by the monomial.
$$ \begin{aligned} \left( 2x^3+18x^2+48x+40 \right) \cdot \color{orangered}{x^2} &= 2x^3 \cdot \color{orangered}{x^2} + 18x^2 \cdot \color{orangered}{x^2} + 48x \cdot \color{orangered}{x^2} + 40 \cdot \color{orangered}{x^2} = \\ &= 2x^5+18x^4+48x^3+40x^2 \end{aligned} $$