\(a,\dfrac{1}{2}+\dfrac{1}{4}+\dfrac{1}{8}+\dfrac{1}{16}=\dfrac{8}{16}+\dfrac{4}{16}+\dfrac{2}{16}+\dfrac{1}{16}=\dfrac{8+4+2+1}{16}=\dfrac{15}{16}\)
\(b,\dfrac{1}{2}+\dfrac{1}{3}+\dfrac{1}{5}=\dfrac{15}{30}+\dfrac{10}{30}+\dfrac{6}{30}=\dfrac{15+10+6}{30}=\dfrac{31}{30}\)
điền dấu < = > vào chỗ chấm
a)\(\dfrac{2}{3}\)+\(\dfrac{1}{4}\)+\(\dfrac{5}{6}\)...\(\dfrac{7}{4}\)
b)\(\dfrac{4}{5}\)+\(\dfrac{2}{3}\)*2-\(\dfrac{1}{5}\)...\(\dfrac{1}{2}\)
c)\(\dfrac{1}{2}\)+\(\dfrac{1}{4}\)+\(\dfrac{1}{8}\)+\(\dfrac{1}{16}\)...\(\dfrac{15}{16}\)
d)\(\dfrac{1515:101}{2525:101}\)...\(\dfrac{3}{5}\)
a.\(\dfrac{2}{3}\times\dfrac{1}{4}-\dfrac{1}{3}\times\dfrac{1}{2}\) =
b.\(\dfrac{8}{5}\times\dfrac{1}{4}-\dfrac{2}{5}\times\dfrac{1}{2}-\dfrac{1}{2}\times\dfrac{1}{5}=\)
giải rõ ràng cho mình nhé
tính thuận tiện:
\(\dfrac{4}{5}+\dfrac{2}{3}+\dfrac{1}{5}+\dfrac{1}{3}\) \(\dfrac{17}{12}+\dfrac{29}{7}-\dfrac{8}{7}+\dfrac{7}{12}\) \(\dfrac{9}{15}+\dfrac{16}{7}+\dfrac{2}{5}-\dfrac{1}{7}-\dfrac{2}{14}\)
\(\dfrac{2}{5}+\dfrac{6}{9}+\dfrac{7}{4}+\dfrac{3}{5}+\dfrac{1}{3}+\dfrac{1}{4}\)
mik sẽ chỉ tick 3 bn xong trước phải chi tiết rõ ràng
a,\(\dfrac{2}{3}\)x\(\dfrac{5}{2}\):\(\dfrac{9}{5}\)
b,\(\dfrac{1}{3}\)x\(\dfrac{1}{4}\)+\(\dfrac{5}{6}\)
c,\(\dfrac{1}{2}\)-\(\dfrac{7}{8}\):\(\dfrac{7}{4}\)
d,\(\dfrac{6}{5}\)-\(\dfrac{4}{5}\)x\(\dfrac{3}{2}\)
a) \(\dfrac{2}{4}\)+\(\dfrac{13}{16}\):\(\dfrac{39}{2}\)
b) \(\dfrac{1}{2}\)x\(\dfrac{3}{5}\)+\(\dfrac{1}{2}\)x\(\dfrac{12}{5}\)
\(\dfrac{2}{5}\) x \(\dfrac{3}{4}-\dfrac{1}{8}\) \(= \)
\(\dfrac{4}{3}+\dfrac{1}{3}-\dfrac{1}{5}=\)
\(\dfrac{9}{20}-\dfrac{3}{5}\) x \(\dfrac{1}{4}\)\(= \)
\(\dfrac{2}{8}+\dfrac{2}{3}:\dfrac{4}{5}\)\(=\)
a,5+\(\dfrac{2}{3}\)
b,\(\dfrac{15}{5}\)x\(\dfrac{1}{4}\)
c.\(\dfrac{3}{8}\)\(-\)\(\dfrac{1}{3}\)
d,\(\dfrac{6}{15}\)\(-\)\(\dfrac{1}{3}\):\(\dfrac{5}{3}\)
Bài 1: Quy đồng mẫu số các phân số sau
a) \(\dfrac{1}{2}\);\(\dfrac{2}{3}\) và \(\dfrac{3}{4}\)
b) \(\dfrac{1}{3}\);\(\dfrac{2}{15}\) và \(\dfrac{4}{45}\)
c) \(\dfrac{1}{8}\);\(\dfrac{2}{3}\) và \(\dfrac{5}{2}\)
d) \(\dfrac{2}{7}\);\(\dfrac{9}{4}\) và \(\dfrac{5}{28}\)
(Các bạn ko cần viết kết luận đâu ah!)
Bài 2:
a) Hãy viết 4 và \(\dfrac{9}{4}\) thành hai phân số có mẫu số chung là 12.
b) Hãy viết \(\dfrac{5}{8}\);\(\dfrac{25}{30}\) và 2 thành các phân số có mẫu số chung là 240.
\(A=\dfrac{19+\dfrac{18}{2}+\dfrac{17}{3}+\dfrac{16}{4}+...+\dfrac{2}{18}+\dfrac{1}{19}}{\dfrac{1}{2}+\dfrac{1}{3}+\dfrac{1}{4}+...+\dfrac{1}{19}+\dfrac{1}{20}}\)
