Simplify the given expression.

4(a)10(b2)412a2(b)5a5=\displaystyle \frac{{-{4}{\left(-{a}\right)}^{{10}}{\left({b}^{{2}}\right)}^{{4}}}}{{{12}{a}^{{2}}{\left(-{b}\right)}^{{5}}{a}^{{5}}}}=