\(\frac{3}{14}:\frac{1}{28}-\frac{13}{21}:\frac{1}{28}-8=\left(\frac{3}{14}-\frac{13}{21}\right):\frac{1}{28}-8=-\frac{17}{42}.28-8=-\frac{34}{3}-8=-\frac{58}{3}\)

\(\frac{3}{14}:\frac{1}{28}-\frac{13}{21}:\frac{1}{28}-8\)

\(=\left(\frac{3}{14}-\frac{13}{21}\right):\frac{1}{28}-8\)

\(=-\frac{17}{42}:\frac{1}{28}-8\)

\(=-\frac{34}{3}-8\)

\(=-\frac{58}{3}\)

Đúng hết ròi                

quy đồng nha bạn

(1-1/15).(1-1/21).(1-1/28)...(1-1/210)          

xin loi nhung ma minh cung dang khong giai duoc cau nay, minh mong cac ban tren Online Math giup minh nhe

bằng \(-\frac{2}{3}\)

nhé

bằng phân số \(\frac{-2}{3}\)nhé nhớ tích nhé

\(\frac{-2}{3}\)

\(\left(1-\frac{1}{21}\right).\left(1-\frac{1}{28}\right).\left(1-\frac{1}{36}\right)...\left(1-\frac{1}{1326}\right)\)

\(=\frac{20}{21}.\frac{27}{28}.\frac{35}{36}...\frac{1325}{1326}\)

\(=\frac{40}{42}.\frac{54}{56}.\frac{70}{72}...\frac{2650}{2652}\)

\(=\frac{5.8}{6.7}.\frac{6.9}{7.8}.\frac{7.10}{8.9}...\frac{50.53}{51.52}\)

\(=\frac{5.6.7...50}{7.8.9...52}.\frac{8.9.10...53}{6.7.8...51}\)

\(=\frac{5.6}{51.52}.\frac{52.53}{6.7}\)

\(=\frac{5.52}{51.7}=\frac{260}{357}\)

Ủng hộ mk nha ^_-

\(\frac{9620}{979}\)

\(\left(\frac{-1}{4}+\frac{7}{33}-\frac{5}{3}\right)-\left(\frac{-5}{4}+\frac{6}{11}-\frac{48}{49}\right)=\left(\frac{-1}{4}-\frac{16}{11}\right)-\left(-\frac{31}{44}-\frac{48}{49}\right)=-\frac{1}{4}-\frac{16}{11}+\frac{31}{44}+\frac{48}{49}=-\frac{1}{49}\)