Đề của bn sai rùi, phải là A = 10101 x ... chứ
\(A=10101.\left(\frac{5}{111111}+\frac{5}{222222}-\frac{4}{3.7.11.13.37}\right)\)
\(A=10101.\left(\frac{5}{10101.11}+\frac{5}{10101.22}-\frac{4}{10101.11}\right)\)
\(A=10101.\frac{1}{10101}.\left(\frac{5}{11}+\frac{5}{22}-\frac{4}{11}\right)\)
\(A=\frac{10}{22}+\frac{5}{22}-\frac{8}{22}\)
\(A=\frac{15}{22}-\frac{8}{22}\)
\(A=\frac{7}{22}\)
Ủng hộ mk nha ^_-