УПРОСТИТЕ ВЫРАЖЕНИЕ ПОМОГИТЕ ПОЖАЛУЙСТА

Решите задачу:

$\left(\dfrac{3}{a-3a^{0.5}}-\dfrac{a^{1.5}}{a^2-9a}\right):\dfrac{a^{0.5}}{a^{0.5}+3}=\left(\dfrac{3}{a^{0.5}(a^{0.5}-3)}-\dfrac{a^{1.5}}{a(a-9)}\right)\cdot\dfrac{a^{0.5}+3}{a^{0.5}}=$

$=\left(\dfrac{3}{a^{0.5}(a^{0.5}-3)}-\dfrac{a^{1.5}}{a(a^{0.5}-3)(a^{0.5}+3)}\right)\cdot\dfrac{a^{0.5}+3}{a^{0.5}}=$

$=\dfrac{3a^{0.5}(a^{0.5}+3)-a^{1.5}}{a(a^{0.5}-3)(a^{0.5}+3)}\cdot\dfrac{a^{0.5}+3}{a^{0.5}}=\dfrac{a^{0.5}(3(a^{0.5}+3)-a)}{a(a^{0.5}-3)(a^{0.5}+3)}\cdot\dfrac{a^{0.5}+3}{a^{0.5}}=$

$=\dfrac{a^{0.5}(3a^{0.5}+9-a)\cdot (a^{0.5}+3)}{a(a^{0.5}-3)(a^{0.5}+3)\cdot a^{0.5}}=\dfrac{3a^{0.5}+9-a}{a(a^{0.5}-3)}$