P = \(\frac{\sqrt{y}.\sqrt{y}-1}{\sqrt{y}\left(\sqrt{y}-1\right)}:\frac{1\left(\sqrt{y}-1\right)+2}{\left(\sqrt{y}-1\right)\left(\sqrt{y}+1\right)}\)
P = \(\frac{y-1}{\sqrt{y}\left(\sqrt{y}-1\right)}:\frac{\sqrt{y}+1}{\left(\sqrt{y}+1\right)\left(\sqrt{y}-1\right)}\)
P = \(\frac{y-1}{\sqrt{y}\left(\sqrt{y}-1\right)}.\frac{\left(\sqrt{y}-1\right)\left(\sqrt{y}+1\right)}{\sqrt{y}+1}=\frac{y-1}{\sqrt{y}}\)
cậu tự tính tiếp nhá