Basic Algebra - 3

$\begin{aligned} y & = {\color{#3D99F6}\left(\frac {x^a}{x^b}\right)^a \left(\frac {x^b}{x^a}\right)^a} \color{#D61F06} \left(\frac {x^a}{x^a}\right)^b \\ & = {\color{#3D99F6}\left(\frac {\cancel{x^a}^1}{\cancel{x^b}}\times \frac {\cancel{x^b}^1}{\cancel{x^a}}\right)^a} \color{#D61F06} \left(\frac {\cancel{x^a}^1}{\cancel{x^a}}\right)^b \\ & = 1^a \times 1^b = \boxed 1 \end{aligned}$

$\left( \frac{x^a}{x^b}\times \frac{x^b}{x^a} \right) ^a \times \left( \frac{x^a}{x^a} \right) ^b=1^a\times1^b=1$