Question

Rút gọn biểu thức M

Answer 1

ĐKXĐ: \(x\notin\left\{0;-2;1;-1\right\}\)

\(M=\dfrac{1}{x^2+2x}-\dfrac{1}{x^2-1}\)

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

\(=\dfrac{-2x-1}{\left(x-1\right)\left(x+1\right)\cdot x\left(x+2\right)}\)