= 2/21

=9/5

=37/6:\(6\frac{1}{6}\)

=79/20: tự đổi nhe bạn

=3/5__________-

\(\frac{4}{15}x\frac{5}{14}=\frac{4x5}{15x14}=\frac{2x1}{3x7}=\frac{2}{21}\)

\(\frac{3}{4}:\frac{5}{12}=\frac{3}{4}x\frac{12}{5}=\frac{3x12}{4x5}=\frac{3x3}{1x5}=\frac{9}{5}=1,8\)

\(\frac{7}{2}+\frac{8}{3}=\frac{7x3}{2x3}+\frac{8x2}{3x2}=\frac{21}{6}+\frac{16}{6}=\frac{21+16}{6}=\frac{37}{6}\)

\(3+\frac{2}{5}-\frac{3}{4}\times\frac{4}{5}\)

\(=3+\frac{2}{5}+\frac{3}{5}\)

\(=3+1\)

\(=4\)

Câu 1\(\frac{9}{8}.\frac{9}{3}=\frac{81}{24}\)

Câu 2 \(\frac{19}{5}+\frac{9}{5}=\frac{28}{5}\)

Câu 3 \(\frac{31}{7}:\frac{22}{5}=\frac{31.5}{7.22}=\frac{155}{154}\)

Câu 4 \(\frac{12}{1}-\frac{31}{5}=\frac{60}{5}-\frac{31}{5}=\frac{29}{5}\)

ai k mình mình k lại

A)\(\frac{4}{3}\times\frac{9}{5}-\frac{6}{5}+3\)

\(=\frac{12}{5}-\frac{6}{5}+3\)

\(=\frac{6}{5}+3\)

\(=3\frac{6}{5}\)

B) \(\frac{5}{3}\div4\div\frac{3}{7}\)

\(=\frac{5}{12}\div\frac{3}{7}\)

\(=\frac{35}{36}\)

C) \(1\frac{3}{4}\div2\frac{3}{5}\)

\(=\frac{7}{4}\div\frac{13}{5}\)

\(=\frac{35}{52}\)

CHÚC BẠN HỌC TỐT!!

\(\frac{4}{3}.\frac{9}{5}-\frac{6}{5}+3=\frac{21}{5}\)

\(\frac{5}{3}:4:\frac{3}{7}=\frac{35}{36}\)

\(1\frac{3}{4}:2\frac{3}{5}=\frac{35}{52}\)

\(3+\frac{2}{5}-\frac{3}{4}\)X \(\frac{4}{5}\)

\(=\frac{3}{1}+\frac{2}{5}-\frac{3}{5}\)

\(=\frac{17}{5}-\frac{3}{5}\)

\(=\frac{14}{5}\)

\(3+\frac{2}{5}-\frac{3}{4}\times\frac{4}{5}\)

\(=3+\frac{2}{5}-\frac{3}{5}\)

\(=3+\frac{-1}{5}\)

\(=\frac{15}{5}+\frac{-1}{5}\)

\(=\frac{14}{5}\)

\(\frac{2}{3}.\frac{4}{5}+\frac{1}{3}.\frac{4}{5}=\frac{4}{5}\left(\frac{2}{3}+\frac{1}{3}\right)=\frac{4}{5}.\frac{3}{3}=\frac{4}{5}.1=\frac{4}{5}\)

\(\frac{1}{2}:\frac{3}{4}+\frac{1}{6}:\frac{3}{4}=\frac{3}{4}:\left(\frac{1}{2}+\frac{1}{6}\right)=\frac{3}{4}:\frac{2}{3}=\frac{9}{8}\)

\(\frac{2}{3}.\frac{4}{5}-\frac{1}{3}.\frac{4}{5}=\frac{4}{5}\left(\frac{2}{3}-\frac{1}{3}\right)=\frac{4}{5}.\frac{1}{3}=\frac{4}{15}\)

\(\frac{1}{2}:\frac{3}{4}-\frac{1}{6}:\frac{3}{4}=\frac{3}{4}:\left(\frac{1}{2}-\frac{1}{6}\right)=\frac{3}{4}:\frac{1}{3}=\frac{9}{4}\)

\(\frac{2}{3}.\frac{4}{5}+\frac{1}{3}.\frac{4}{5}=\left(\frac{2}{3}+\frac{1}{3}\right).\frac{4}{5}=1.\frac{4}{5}=\frac{4}{5}\)

\(\frac{1}{2}:\frac{3}{4}+\frac{1}{6}:\frac{3}{4}=\frac{1}{2}.\frac{4}{3}+\frac{1}{6}.\frac{4}{3}=\left(\frac{1}{2}+\frac{1}{6}\right).\frac{4}{3}=\frac{2}{3}.\frac{4}{3}=\frac{8}{9}\)

c,d tương tự 

\(\frac{1}{2\cdot3}+\frac{1}{3\cdot4}+\frac{1}{4\cdot5}+\frac{1}{5\cdot6}\)

\(=\frac12-\frac13+\frac13-\frac14+\frac14-\frac15+\frac15-\frac16\)

\(=\frac12-\frac16\)

\(=\frac13\)

Mình tính từng bước cẩn thận nhé: \frac{1}{2} \times 3 + \frac{1}{3} \times 4 + \frac{1}{4} \times 5 + \frac{1}{5} \times 6 1. 2. 3. 4. Bây giờ cộng lại: \frac{3}{2} + \frac{4}{3} + \frac{5}{4} + \frac{6}{5} Quy đồng mẫu chung là : Cộng lại: 90 + 80 + 75 + 72 = 317 Vậy kết quả: \frac{317}{60} ≈ 5,2833…

a, Sai

b, Đúng

c, đúng 

d, Sai

a,\(2\frac{2}{5}+1\frac{2}{5}=3\frac{2}{5}\left(S\right)\)

b,\(6\frac{3}{4}-1\frac{1}{4}=5\frac{2}{4}\left(\text{Đ}\right)\)

c,\(3\frac{1}{2}\times2\frac{2}{3}=9\frac{1}{3}\left(\text{Đ}\right)\)

d,\(4\frac{1}{6}\div2\frac{1}{5}=2\frac{5}{6}\left(S\right)\)

đưa hết hỗn số về dạng phân số rồi quy đồng bình thường ạ !

Hoàng_Linh_Nga làm đc thì làm nhé.

Giải:

\(2\frac{1}{6}+3\frac{2}{3}\)

\(=\frac{13}{12}+\frac{11}{9}\)

\(=\frac{249}{108}\)

\(4\frac{3}{4}-3\frac{5}{6}\)

\(=\frac{19}{16}-\frac{23}{18}\)

\(=\frac{342}{288}-\frac{368}{288}\)

\(=\frac{-26}{288}\)xem lại đề đi nhé

\(9\frac{1}{6}\times4\frac{2}{3}\)

\(=\frac{55}{18}\times\frac{15}{12}\)

\(=\frac{825}{216}\)

\(2\frac{5}{7}:\frac{14}{5}\)

\(=\frac{19}{7}:\frac{14}{5}\)

\(=\frac{95}{98}\)