Question

1.rút gọn biểu thức:  \(C=\frac{3}{3a-1}.\sqrt{5a.\left(1-6a+9a^2\right)}\)với a>1/3

Answer 1

\(C=\frac{3}{3a-1}\sqrt{5a\left(1-6a+9a^2\right)}=\frac{3}{3a-1}\sqrt{5a\left(1-3a\right)^2}=\frac{3}{3a-1}\sqrt{5a}\left(3a-1\right)\) (Vì a>1/3 nên 1-3a<0

\(=3\sqrt{5a}\)

Answer 2

\(C=\frac{3}{3a-1}\cdot\sqrt{5a}l1-3al\)

   \(=\frac{3}{3a-1}\cdot\sqrt{5a}\cdot\left(3a-1\right)\)  ( vì a > 1/3)

     = \(3\sqrt{5a}\)