Question

What is the product of 
`k^(3) + 9k^(2) + 3` and 
`7k^(2) - 5`?

Answer 1

(k³+9k²+3)(7k²-5)=

=k³·7k²+k³ ·(-5)+9k² · 7k²+9k² ·(-5)+ 3· 7k²+3·(-5)=

=7k^5-5k³+63k^4-45k²+21k²-15=

=7k^5+63k^4-5k³-24k²-15