\(\dfrac{\left(-2\right)^5.\left(-3\right)^7}{2^6.\left(-3\right)^6}=\dfrac{\dfrac{\left(-2\right)^5}{\left(-2\right)^5}\cdot\dfrac{\left(-3\right)^7}{\left(-3\right)^6}}{\dfrac{2^6}{\left(-2\right)^5}\cdot\dfrac{\left(-3\right)^6}{\left(-3\right)^6}}=\dfrac{1.\left(-3\right)}{-2.1}=\dfrac{3}{2}\)