I need help with this whole unit if anyone can help

In factoring by grouping, what would you have for step 3 for the following? step 1: x^3 +5x^2 +4x+20 step 2: x^2 (x+5)+4(x+5) step 3: ?

F(x) = 1/x g(x)=x-4 can you evaluate (g*f)(0) ? why or why not?

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.