Algebra help- simplifying and factorising?

Simplify-
3x(squared)y X 4xy(cubed)
4t X 2q

Factorise-
-3x-9

Oh and expand-
4x(x'squared'+5)
-5(p-4)

Sorry if its confusing, I don't know how to get a squared or cubed sign on iPhone.

Hopefully you mean:

3x(squared)y X 4xy(cubed) as 3(x^2)y X 4x(y^3) which is 12(x^3)(y^4).
4t X 2q = 8qt

-3x-9 = -3(x+3) (take common factor out)

4x(x'squared'+5) = 4x. X^2)+5) = 4(x^3)+20x
-5(p-4) = -5p+20