=3/2*4/3*5/4...*11/10

=5,5

\(1\frac{1}{2}x1\frac{1}{3}:1\frac{1}{4}:1\frac{1}{5}\)

\(=\frac{3}{2}x\frac{4}{3}:\frac{5}{4}:\frac{6}{5}\)

\(=\frac{3}{2}x\frac{4}{3}x\frac{4}{5}x\frac{5}{6}\)

\(=\frac{4x4}{2x6}=\frac{2x2x4}{2x2x3}=\frac{4}{3}\)

\(1\frac{1}{2}\times1\frac{1}{3}\div1\frac{1}{4}\div1\frac{1}{5}=\frac{3}{2}\times\frac{4}{3}\div\frac{5}{4}\div\frac{6}{5}=\frac{3}{2}\times\frac{4}{3}\times\frac{4}{5}\times\frac{5}{6}\)

                                           \(=\frac{3\times4\times4\times5}{2\times3\times5\times6}=\frac{4}{3}\)

\(1\frac{1}{2}\times1\frac{1}{3}:1\frac{1}{4}:1\frac{1}{5}\)

\(=\frac{3}{2}\times\frac{4}{3}:\frac{5}{4}:\frac{6}{5}\)

\(=\frac{3}{2}\times\frac{4}{3}\times\frac{4}{5}\times\frac{5}{6}\)

\(=\frac{3\times4\times4\times5}{2\times3\times5\times6}\)

\(=\frac{4\times4}{2\times6}\)

\(=\frac{2\times2\times4}{2\times2\times3}\)

\(=\frac{4}{3}\)

_Chúc bạn học tốt_

Trả lời

\(\frac{1}{2}:\frac{3}{4}+\frac{1}{6}:\frac{3}{4}\)

\(=\frac{1}{2}.\frac{4}{3}+\frac{1}{6}.\frac{4}{3}\)

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

\(=\frac{4}{3}.\frac{2}{3}\)

\(=\frac{8}{9}\)

Bạn ơi cho mình hỏi là tại sao lại có \(\frac{4}{3}\)ạ

\(\frac{1}{2}\div\frac{3}{4}+\frac{1}{6}\div\frac{3}{4}\)

\(\Leftrightarrow\frac{1}{2}\times\frac{4}{3}+\frac{1}{6}\times\frac{4}{3}\)

\(=\frac{4}{3}\times\left(\frac{3}{6}+\frac{1}{6}\right)\)

\(=\frac{4}{3}\times\frac{4}{6}\)

\(=\frac{16}{18}\)

\(=\frac{8}{9}\)

~Std well~

#ChiChinMin

\(\left(1-\frac{1}{2}\right)x\left(1-\frac{1}{3}\right)x\left(1-\frac{1}{4}\right)x\left(1-\frac{1}{5}\right)x\left(1-\frac{1}{6}\right)\)

\(=\frac{1}{2}.\frac{2}{3}.\frac{3}{4}.\frac{4}{5}.\frac{5}{6}\)

\(=\frac{1.2.3.4.5}{2.3.4.5.6}=\frac{1}{6}\)

Phạm Tuấn Đạt làm đúng rồi đó

Mình cũng làm theo bạn ấy

(1 - 1/2) x (1 - 1/3) x (1 - 1/4) x (1 - 1/5) x (1 - 1/6)

= 1/2 x 2/3 x 3/4 x 4/5 x 5/6

= 1/6 (tử và mẫu triệt tiêu cho nhau)

Đặt \(A=1+\frac{1}{3}+\frac{1}{9}+\frac{1}{27}+\frac{1}{81}+\frac{1}{243}\)

\(A=1+\frac{1}{3}+\frac{1}{3^2}+...+\frac{1}{3^5}\)

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

\(3A=3+1+...+\frac{1}{3^4}\)

\(3A-A=\left(3+1+...+\frac{1}{3^4}\right)-\left(1+\frac{1}{3}+...+\frac{1}{3^5}\right)\)

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

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

Đặt \(S=1+\frac{1}{3}+\frac{1}{9}+\frac{1}{27}+\frac{1}{81}+\frac{1}{243}\)

      \(S=1+\frac{1}{1\times3}+\frac{1}{3\times3}+\frac{1}{9\times3}+\frac{1}{27\times3}+\frac{1}{81\times3}\)

\(S\times3=\left(1+\frac{1}{1\times3}+\frac{1}{3\times3}+\frac{1}{9\times3}+\frac{1}{27\times3}+\frac{1}{81\times3}\right)\times3\)

\(S\times3=3+1+\frac{1}{3}+\frac{1}{9}+\frac{1}{27}+\frac{1}{81}\)

Xét: \(S\times3-S=\left(3+1+\frac{1}{3}+\frac{1}{9}+\frac{1}{27}+\frac{1}{81}\right)-\left(1+\frac{1}{3}+\frac{1}{9}+\frac{1}{27}+\frac{1}{81}+\frac{1}{243}\right)\)

              \(S\times2=3-\frac{1}{243}\)

              \(S\times2=\frac{728}{243}\)

                    \(S=\frac{728}{243}\div2\)

                    \(S=\frac{364}{243}\)

Vậy \(1+\frac{1}{3}+\frac{1}{9}+\frac{1}{27}+\frac{1}{81}+\frac{1}{243}=\frac{364}{243}\)

khó vậy nhỉ

\(\frac{1}{3}+\frac{1}{4}+\frac{1}{5}+\frac{4}{6}+\frac{9}{12}+\frac{16}{20}=\left(\frac{1}{3}+\frac{4}{6}\right)+\left(\frac{1}{4}+\frac{9}{12}\right)+\left(\frac{1}{5}+\frac{16}{20}\right)\)

\(=1+1+1=3\)

Ta có\(\frac{1}{3}+\frac{1}{4}+\frac{1}{5}+\frac{4}{6}+\frac{9}{12}+\frac{16}{20}=\left(\frac{1}{3}+\frac{4}{6}\right)+\left(\frac{1}{4}+\frac{9}{12}\right)+\left(\frac{1}{5}+\frac{16}{20}\right)\)

\(=\left(\frac{2+4}{6}\right)+\left(\frac{3+9}{12}\right)+\left(\frac{4+16}{20}\right)\)

\(=\frac{6}{6}+\frac{12}{12}+\frac{20}{20}\)

\(=1+1+1\)

\(=3\)

\(\frac{24}{75}\): \(\frac{8}{15}\)X \(\frac{10}{9}\) = \(\frac{24}{75}\) X \(\frac{15}{8}\)X \(\frac{10}{9}\)= \(\frac{8x3x5x3x5x2}{15x5x8x3x3}\)= \(\frac{2}{3}\)

mình trả lời nhanh nhất nha, nhớ tk cho mình đấy

2/3 nha bn, bn k đi r mk kb cho

Mk tính bằng 2/3 

Nếu đúng thì k mk nhé! Kb luôn nha