Trừ các phân thức sau: (x+1)/(x-5)-(1-x)/(x+5)-2x(1-x)/25-x^2 với x khác +-5
Giải thích
Ta có x+1x−5−1−xx+5−2x(1−x)25−x2=x+1x−5−1−xx+5+2x(1−x)(x−5)(x+5)
=(x+1)(x+5)−(1−x)(x−5)+2x(1−x)(x−5)(x+5)=2x−5
Ta có x+1x−5−1−xx+5−2x(1−x)25−x2=x+1x−5−1−xx+5+2x(1−x)(x−5)(x+5)
=(x+1)(x+5)−(1−x)(x−5)+2x(1−x)(x−5)(x+5)=2x−5