Cho biểu thức: P=căn x/(căn x+2)+(−x+xcănx+6)/(x+cănx−2)−(cănx+1)/(cănx−1) với
Giải thích
Ta có:
P=xx+2+−x+xx+6x+x−2−x+1x−1=xx−1−x+xx+6−x+1x+2x−1x+2=x−x−x+xx+6−x−3x−2x−1x+2=−x+xx−4x+4x−1x+2=x−1x−4x−1x+2=x−2
Ta có:
P=xx+2+−x+xx+6x+x−2−x+1x−1=xx−1−x+xx+6−x+1x+2x−1x+2=x−x−x+xx+6−x−3x−2x−1x+2=−x+xx−4x+4x−1x+2=x−1x−4x−1x+2=x−2