For this problem, you will need to foil. Multiply each term in the first expression (5r-7) by each term in the second expression (9r^2-4r-8)
When we foil, we get:
[tex] 45r^3-20r^2-40r-63r^2+28r+56 [/tex]
Combine like terms:
[tex] 45r^3-83r^2-12r+56 [/tex]
This is your final answer since you can do nothing further to simplify.
