Question

rút gọn bt sau : \(\sqrt{1-a}\sqrt{a\left(a-1\right)}+a\sqrt{\frac{a-1}{a}}\)

Answer 1

ĐK a < 0 hoặc a = 1 

\(=\sqrt{1-a}+\sqrt{a\left(a-1\right)}-\sqrt{\frac{a^2\left(a-1\right)}{a}}=\sqrt{1-a}+\sqrt{a\left(a-1\right)}-\sqrt{a\left(a-1\right)}=\sqrt{1-a}\)

Answer 2

Đk \(1-a\ge0;a\left(1-a\right)\ge0;\frac{a}{a-1}\ge0\)

=> \(a\le1;a\ge1ora\le0;a\ge1ora