Question

rút gọn, tính 

C=(1-\(\dfrac{a+\sqrt{a}}{\sqrt{a}+1}\)) .(1+\(\dfrac{a-\sqrt{a}}{\sqrt{a}-1}\))

Answer 1

ĐKXĐ: \(a\ge0;a\ne1\)

\(C=\left(1-\dfrac{\sqrt{a}\left(\sqrt{a}+1\right)}{\sqrt{a}+1}\right)\left(1+\dfrac{\sqrt{a}\left(\sqrt{a}-1\right)}{\sqrt{a}-1}\right)\)

\(=\left(1-\sqrt{a}\right)\left(1+\sqrt{a}\right)=1-a\)

Answer 2

Ta có: \(C=\left(1-\dfrac{a+\sqrt{a}}{\sqrt{a}+1}\right)\left(1+\dfrac{a-\sqrt{a}}{\sqrt{a}-1}\right)\)

\(=\left(1-\sqrt{a}\right)\left(1+\sqrt{a}\right)\)

=1-a