If the function be defined as and be defined as , show that .

If the function $f : \mathbb{R} \to \mathbb{R}$ be defined as $f(x) = \frac{3x + 4}{5x - 7}, x \ne \frac{7}{5}$ and $g : \mathbb{R} \to \mathbb{R}$ be defined as $g(x) = \frac{7x + 4}{5x - 3}, x \ne \frac{3}{5}$, show that $(g \circ f)(x) = (f \circ g)(x)$.