Simplify the following expressions in which a, x and y are real numbers greater than 0.
\dfrac{a^3.a^{-2}.a^{1/4}}{a^2.a^{-1}}
\dfrac{2\times2^{-2}\times2^{4}}{2^{3}\times2^{1/2}}
\dfrac{a^3.a^{-1/2}}{a^2.a^{1/2}.a}
\dfrac{2^{3/2}.x^3.y^{-2}}{2^{5/2}.x^{1/3}.y^{1/2}}
\dfrac{\left(a^3.a^{-1/4}\right)^4}{\left(a^{1/3}.a^{-1/2}\right)^3}\\\\\\
\dfrac{4\times 5^{-1/2}\times 5^{3}}{5^{4}\times 4^{1/2}}
\dfrac{\left(a^3.b^{-1/6}\right)^3}{\left(a^{-2}.b^{-1/2}\right)^2}\\\\\\