Rút gọn biểu thức: A=1/(x+cănx)−2cănx/(x−1)+1/(x−cănx
Giải thích
A=1x+x−2xx−1+1x−x=1x(x+1)−2x(x−1)(x+1)+1x(x−1)=(x−1)−2xx+(x+1)x(x−1)(x+1)=−2x+2xx(x−1)(x+1)=−2x(x−1)x(x−1)(x+1)=−2x+1
A=1x+x−2xx−1+1x−x=1x(x+1)−2x(x−1)(x+1)+1x(x−1)=(x−1)−2xx+(x+1)x(x−1)(x+1)=−2x+2xx(x−1)(x+1)=−2x(x−1)x(x−1)(x+1)=−2x+1