\(A=\frac{1}{10}-\frac{1}{13}+\frac{1}{13}-\frac{1}{16}+\frac{1}{16}-\frac{1}{19}+...+\frac{1}{58}-\frac{1}{61}\)
\(A=\frac{1}{10}-\frac{1}{61}=\frac{51}{610}\)
A=3/10.13 +3/13.16+ 3/16.19+....+3/58.61
A=1/10.13+1/13.16+1/16.19+.....+1/58.61
A=1/10- 1/13+ 1/13- 1/16+ 1/16- 1/19+...+1/58 –1/61
A=1/10 – 1/61
A= 61/610 – 10/610
A= 51/610
Mình giải xong rồi k nhá?
\(=\frac{1}{10}-\frac{1}{13}+\frac{1}{13}-\frac{1}{16}+...+\frac{1}{58}-\frac{1}{61}\)
\(=\frac{1}{10}-\frac{1}{61}\)
\(=\frac{51}{610}\)