Question

Termenul al cincilea al dezvoltării (
$(\sqrt{x } + \sqrt{y} ) {}^{9}$
​

Answer 1

$\it T_{5}=T_{4+1}=\Big C^5_9\cdot(\sqrt x)^4\cdot(\sqrt y)^5=\dfrac{9!}{5!\cdot4!}x^2y^2\sqrt y=126x^2y^2\sqrt y$