We have two polynomials:
[tex]\begin{gathered} p(x)=3x^2-4 \\ r(x)=2x^2-5x+1 \end{gathered}[/tex]We have to find -5*r*(2a). This can be written as:
[tex]-5\cdot r\cdot(2a)=(-5\cdot2a)\cdot r=-10a\cdot r[/tex][tex]\begin{gathered} -10a\cdot r(x)=-10a\cdot(2x^2-5x+1) \\ -10a\cdot2x^2-10a(-5x)-10a\cdot1 \\ -20ax^2+50ax-10a \end{gathered}[/tex]Answer: -5r(2a) = -20ax^2+50ax-10a