Multiply Variable Expressions

Multiply the terms. 

1. $x \cdot x = $
2. $y \cdot y^2 \cdot y^3 = $
3. $2x \cdot 4x^3 \cdot 9x^{12} = $
4. $a^2 \cdot b^4 \cdot 6c^3 = $
5. $x^2 \cdot 4x^3 \cdot 3xy^3 = $
6. $(5abc)(3bc)(2ac) = $
7. $(3x^2y^3)(3xyz)(6x^6y) = $
8. $(2x^2)(3xy^7)(5ac)(7a^3c^5) = $
9. $(\dfrac{1}{2}a^2)(4b^4)= $
10. $\dfrac{a}{b^2} \cdot \dfrac{b^5}{a^7} \cdot \dfrac{1}{5} = $