How do you simplify  (12x^5) /( 3x^7)?

It is $\frac{12 {x}^{5}}{3 {x}^{7}} = \frac{3 \cdot 4 \cdot {x}^{5}}{3 \cdot {x}^{5} \cdot {x}^{2}} = \frac{4}{x} ^ 2$