Thực hiện các phép tính sau: a) 1/ x+ 2/ x+1+ 3/ x+2- 1/ x- 2/ x-1- 3/ x+2 ;
Giải thích
a, 1x+2x+1+3x+2−1x−2x−1−3x+2=1x−1x+2x+1−2x−1+3x+2−3x+2
0+2(x−1)−2(x+1)(x−1)(x+1)+0=−4(x+1)(x−1)=−4x2−1
a, 1x+2x+1+3x+2−1x−2x−1−3x+2=1x−1x+2x+1−2x−1+3x+2−3x+2
0+2(x−1)−2(x+1)(x−1)(x+1)+0=−4(x+1)(x−1)=−4x2−1