2\(\frac{2}{12}\)+ X = \(\frac{5}{7}\)+ \(\frac{8}{12}\)

\(\frac{13}{6}\)+ X=\(\frac{29}{21}\)

X= \(\frac{29}{21}\)- \(\frac{13}{6}\)

X=\(\frac{-11}{14}\)

\(|2^2_{12}\)\(+x=\frac{5}{7}+\frac{8}{12}\)

\(2+x=\frac{5}{7}+\frac{1}{2}\)

\(2+x=\frac{17}{14}\)

\(x=\frac{17}{14}-2\)

\(x=\frac{-11}{14}\)

\(9\frac{5}{34}-12+5\)

\(9\frac{5}{34}=\frac{311}{34}\)

\(\Rightarrow9\frac{5}{34}-12+5\)

\(=\frac{311}{34}-12+5\)

\(=-\frac{97}{34}+5\)

\(=\frac{73}{34}\)

= \(\frac{69}{34}\)

Mk kb rùi đó , tk mk nha !

Bài 1 : 

a) \(\frac{6}{10}\)

Bài 2 :

c) \(\frac{8}{18}\)

Bài 1:

Kết quả:\(\frac{6}{10}\)

Bài 2:

Kết quả:\(\frac{8}{18}\)

                                                                                           K CHO MK NHA:   

                                                                                                  KÍ TÊN

                                                                              \(!@#HUYDEPZAI\%\&\)

\(\frac{10}{18}+\frac{4}{9}+\frac{26}{10}+\frac{12}{5}+\frac{9}{15}\)

\(=\frac{5}{9}+\frac{4}{9}+\frac{13}{5}+\frac{12}{5}+\frac{3}{5}\)

\(=\left(\frac{5}{9}+\frac{4}{9}\right)+\left(\frac{13}{5}+\frac{12}{5}+\frac{3}{5}\right)\)

\(=1+\frac{28}{5}\)

\(=\frac{33}{5}\)

Ta có:

a) \(\frac{10}{18}+\frac{4}{9}+\frac{26}{10}+\frac{12}{5}+\frac{9}{15}=\frac{5}{9}+\frac{4}{9}+\frac{13}{5}+\frac{12}{5}+\frac{9}{15}=1+1+\frac{9}{15}=1\frac{9}{15}\)

b)\(\frac{10}{18}+\frac{4}{9}+\frac{1}{8}+\frac{1}{16}+\frac{1}{32}+\frac{1}{64}+\frac{1}{128}=\left(\frac{5}{9}+\frac{4}{9}\right)+\left(\frac{16}{128}+\frac{8}{128}+\frac{4}{128}+\frac{2}{128}+\frac{1}{128}\right)\)

\(=1+\frac{31}{128}=1\frac{31}{128}\)

\(12\frac{1}{2}\%=\frac{5}{30}\)

ta có:

12 \(\frac{1}{2}\) % = \(\frac{12x2+1}{2}\) % =\(\frac{25}{2}\) % = 12,5:100=0,125

60/225

660/396

198/55

144/252 

k nha bn

a)4/33

b)5/3

c)18/5

d)4/7

1.      \(\frac{3}{1.4}+\frac{3}{4.7}+\frac{3}{7.10}+...+\frac{3}{40.43}\)

\(=1-\frac{1}{4}+\frac{1}{4}-\frac{1}{7}+\frac{1}{7}-\frac{1}{10}+...+\frac{1}{40}-\frac{1}{43}\)

\(=1-\frac{1}{43}\)

\(=\frac{42}{43}\)

2.     Đặt \(A=\frac{2}{2}+\frac{2}{6}+\frac{2}{12}+...+\frac{2}{90}\)

\(=2.\left(\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+...+\frac{1}{9.10}\right)\)

\(=2.\left(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{9}-\frac{1}{10}\right)\)

\(=2.\left(1-\frac{1}{10}\right)\)

\(=2.\frac{9}{10}\)

\(=\frac{9}{5}\)

Ủng hộ mk nha !!! ^_^

1) 3/1×4 + 3/4×7 + 3/7×10 + ... + 3/40×43

= 1 - 1/4 + 1/4 - 1/7 + 1/7 - 1/10 + ... + 1/40 - 1/43

= 1 - 1/43

= 42/43

2) 2/2 + 2/6 + 2/12 + ... + 2/90

= 2 × (1/2 + 1/6 + 1/12 + ... + 1/90)

= 2 × (1/1×2 + 1/2×3 + 1/3×4 + ... + 1/9×10)

= 2 × (1 - 1/2 + 1/2 - 1/3 + 1/3 - 1/4 + ... + 1/9 - 1/10)

= 2 × (1 - 1/10)

= 2 × 9/10

= 9/5

\(12\frac{3}{7}\%+12\frac{5}{7}\%=\frac{176}{7}\%\)

a) \(\frac{2}{5}+\left(\frac{2}{8}+\frac{3}{5}+\frac{6}{8}\right)=\left(\frac{2}{5}+\frac{3}{5}\right)+\left(\frac{2}{8}+\frac{6}{8}\right)=1+1=2\)

b) \(\frac{6}{9}+\left(\frac{15}{25}+\frac{12}{9}+\frac{6}{15}\right)=\left(\frac{6}{9}+\frac{12}{9}\right)+\left(\frac{15}{25}+\frac{6}{15}\right)\)

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