they are excited about the film

they find ...

they will be building

C= \(\frac{2\sqrt{a}+3\sqrt{b}}{\sqrt{ab}+2\sqrt{a}+3\sqrt{b}+6}-\frac{6-\sqrt{ab}}{\sqrt{ab}+2\sqrt{a}+3\sqrt{b}+6}\)

a) Rút gọn C

b)CMR nếu C= \(\frac{b+81}{b-81}\)thì \(\frac{a}{b}\) chia hết cho 3

\(B=1:\left(\frac{x-2}{x\sqrt{x}-1}+\frac{\sqrt{x}+1}{x+\sqrt{x}+1}-\frac{\sqrt{x}+1}{x-1}\right)\)

\(\left(\frac{a^2-ab}{a^2b+b^3}-\frac{2a^2}{b^3-ab^2+a^2b-a3}\right)\cdot\left(1-\frac{b-1}{a}-\frac{b}{a^2}\right)=\frac{a+1}{ab}\)