Question

help :)) 

Answer 1

\(A=\left(\dfrac{\sqrt{a}+1}{\sqrt{a}-1}-\dfrac{\sqrt{a}-1}{\sqrt{a}+1}+4\sqrt{a}\right)\left(\sqrt{a}+\dfrac{1}{\sqrt{a}}\right)\left(dk:x>0,x\ne1\right)\\ =\left[\dfrac{\left(\sqrt{a}+1\right)^2-\left(\sqrt{a}-1\right)^2+4\sqrt{a}\left(a-1\right)}{a-1}\right]\left(\dfrac{a+1}{\sqrt{a}}\right)\)

\(=\left(\dfrac{a+2\sqrt{a}+1-a+2\sqrt{a}-1+4a\sqrt{a}-4\sqrt{a}}{a-1}\right)\left(\dfrac{a+1}{\sqrt{a}}\right)\\ =\dfrac{4a\sqrt{a}}{a-1}.\dfrac{a+1}{\sqrt{a}}\\ =\dfrac{4a\left(a+1\right)}{a-1}\)