Question

Answer 1

1) \(\dfrac{x-7}{6x^2y}+\dfrac{5x+7}{6x^2y}.\left(đk:x\ne0;y\ne0\right).\)

\(=\dfrac{x-7+5x+7}{6x^2y}=\dfrac{6x}{6x^2y}=\dfrac{1}{xy}.\)

2) \(\dfrac{3x-3}{3x}-\dfrac{x-3}{3x}.\left(đk:x\ne0\right).\)

\(=\dfrac{3x-3-x+3}{3x}=\dfrac{2x}{3x}=\dfrac{2}{3}.\)

3) \(\dfrac{3x+1}{x-5}-\dfrac{x+1}{5-x}.\left(đk:x\ne5\right).\)

\(=\dfrac{3x+1+x+1}{x-5}=\dfrac{4x+2}{x-5}.\)

 

Answer 2

4: \(=\dfrac{x^2-6x+9-x^2+9}{x\left(x-3\right)}=\dfrac{-6x+18}{x\left(x-3\right)}=\dfrac{-6}{x}\)