Given the equation;
[tex](5-9r^5)+(-10+8r^3)[/tex]we want to expand and simplify the expression.
[tex]\begin{gathered} (5-9r^5)+(-10+8r^3) \\ 5-9r^5-10+8r^3 \\ \text{ collecting the like terms;} \\ -9r^5+8r^3-10+5 \\ -9r^5+8r^3-5 \end{gathered}[/tex]So, expanding and simplifying the expression we have;
[tex]-9r^5+8r^3-5[/tex]