Cho A = 1/2 + 1/3 + 1/4 + ... + 1/200; B = 1/199 + 2/198 + 3/197 + ... + 198/2
Giải thích
B=1199+2198+3197+...+1982+1991=1199+1+2198+1+...+1982+1+1=200199+200198+...+2002+200200=20012+13+...+1200=200A⇒BA=200AA=200
B=1199+2198+3197+...+1982+1991=1199+1+2198+1+...+1982+1+1=200199+200198+...+2002+200200=20012+13+...+1200=200A⇒BA=200AA=200