[tex]\begin{gathered} (-8a^3-4a^2+10a-6)+(a^3-5a^2-9a+4) \\ (-8a^3+a^3)+(-4a^2-5a^2)+(10a-9a)+(-6+4) \\ -7a^3-9a^2+a-2 \end{gathered}[/tex][tex]\begin{gathered} 5b^2(-3b^3-4b+9) \\ =(5b^2\cdot-3b^3)+(5b^2\cdot-4b)+(5b^2\cdot9) \\ =-15b^5-20b^3+45b^2 \end{gathered}[/tex][tex]\begin{gathered} (c-6)(c+8) \\ (c\cdot c)+(c\cdot8)+(-6\cdot c)+(-6\cdot8) \\ c^2+8c-6c-48\text{ Simplify further and we get} \\ c^2+2c-48 \end{gathered}[/tex]
