Multiplying and Dividing Monomials

Is $$2x+7$$ a monomial?

Is $$\frac{5x}{12}$$ a monomial?

Is $$x^{-3}$$ a monomial?

Is $$\frac{3}{y}$$ a monomial?

Simplify $$\left(-3x^2\right)\left(4x^3\right)$$ as much as possible.

(a)  

Simplify $$\left[\left(2xy^{2\ }\right)^2\right]^3$$ as much as possible.

Simplify $$\frac{6x^5yz^{-2}}{3x^3y^4}$$ as much as possible.

Simplify $$\left(\frac{2r^3t^6}{3u^9}\right)^4$$ as much as possible

Simplify $$\left(2x^2y\right)^3\left(-2xy^3\right)$$ as much as possible.

(a)  

Simplify $$\left(\frac{3x^6y^{12}z}{12x^{10}yz^{13}}\right)^0$$ as much as possible

(a)