How do i solve these problems?

Question

Directions simplipy each by doing the indicated opertions and combing like terms. Theirs no differnt types of problems im confuesed wtih, please show me how to do it, i want to learn so i can do rest of problems

here is one example of a similiar problem im trying to figure out how to solve -3xy cubed(x-2y)

heres another

(-3x squared y cubedz)cubed

Answer 1

-3xy^3(x-2y)

Distribute the -3xy^3 through the parentheses:

(-3xy^3)(x) + (-3xy^3)(-2y)

Multiply the coefficents:

(-3xy^3)(x) + (6xy^3)(y)

Multiply the variables (letters)...if they have the same base, add the exponents together...otherwise, leave them alone:

-3x^2y^3 + 6xy^4

(-3x^2y^3z)^3

Everything inside the parentheses needs to be taken to the power of 3:

(-3)^3(x^2)^3(y^3)^3(z)^3

Coefficients first:

(-3)(-3)(-3)(x^2)^3(y^3)^3(z)^3

-27(x^2)^3(y^3)^3(z)^3

When exponents are taken to another power, the numbers are multiplied together:

-27x^(2*3)y^(3*3)z^(1*3)

-27x^6y^9z^3

Hope that helps!