Question

Rút gọn phân thức \(\dfrac{7\left(3x^2-1\right)}{1-3x^2}\)

Answer 1

\(\dfrac{7\left(3x^2-1\right)}{1-3x^2}\)

= \(\dfrac{-7\left(3x^2-1\right)}{3x^2-1}\)

= -7 

Answer 2

Ta có: \(\dfrac{7\left(3x^2-1\right)}{1-3x^2}\)

\(=\dfrac{-7\cdot\left(1-3x^2\right)}{1-3x^2}\)

=-7