a: =1/2+3/2=2

b: =2/5+7/5=9/5

c: =2/3+2/3=4/3

ai trả lời cho mình vs sos

3/6 + 12/8 = 1/2 + 3/2 = 4/2 = 2

2/5 + 56/40 = 2/5 + 7/5 = 9/5

4/6 + 16/24 = 2/3 + 2/3 = 4/3

\(\dfrac{4}{9}\cdot\dfrac{35}{118}+\dfrac{5}{9}\cdot\dfrac{35}{118}-\dfrac{35}{118}\\ =\dfrac{38}{118}\left(\dfrac{4}{9}+\dfrac{5}{9}-1\right)\\ =\dfrac{38}{118}\cdot0=0\)

\(\dfrac{4}{9}\cdot\dfrac{35}{118}+\dfrac{5}{9}\cdot\dfrac{35}{118}-\dfrac{35}{118}\)

\(=\dfrac{35}{118}\left(\dfrac{4}{9}+\dfrac{5}{9}-1\right)\)

=0

a: =(-5-5)/9=-10/9

b: =1/4+1/5=9/20

c: =-11/2+2/2=-9/2

a)-10/9

b)9/20

c)-9/2

sai thì sorry

a) \(\dfrac{-5}{9}-\dfrac{5}{9}=\dfrac{\left(-5\right)-5}{9}=\dfrac{-\left(5+5\right)}{9}=\dfrac{-10}{9}\)

b) \(\dfrac{9}{36}-\dfrac{7}{-35}=\dfrac{1}{4}+\dfrac{1}{-5}=\dfrac{9}{-20}\)

c) \(\dfrac{-11}{2}-\left(-1\right)=\dfrac{-11}{2}+\dfrac{2}{2}=\dfrac{9}{2}\)

B nhé 

HT

Chọn B nha bạn

B. 

a) \(\frac{25}{5}\); \(\frac{7}{3}\) ;   \(\frac{25}{35}\); \(\frac{5}{8}\); \(\frac{21}{56}\)

b) \(\frac{9}{2}\) ; \(\frac{9}{7}\);  \(\frac{25}{50}\); \(\frac{2}{9}\); \(\frac{1}{5}\)

k cho mk nha

\(\frac{18}{7}:9=\frac{18}{7}:\frac{9}{1}=\frac{18}{7}×\frac{1}{9}=\frac{9×2×1}{7×9}=\frac{2}{7}\)

\(\frac{64}{35}:4=\frac{64}{35}:\frac{4}{1}=\frac{64}{35}×\frac{1}{4}=\frac{16×4×1}{35×4}=\frac{16}{35}\)

\(\frac{24}{11}:12=\frac{24}{11}:\frac{12}{1}=\frac{24}{11}×\frac{1}{12}=\frac{12×2×1}{11×12}=\frac{2}{11}\)

\(\frac{35}{14}:5=\frac{35}{14}:\frac{5}{1}=\frac{35}{14}×\frac{1}{5}=\frac{5×7×1}{14×5}=\frac{7}{14}=\frac{1}{2}\)

18/17:9=18/17:9/1=18/17x1/9=2/17

64/35:4=64/35:4/1=64/35x1/4=16/35

24/11:12=24/11:12/1=24/11x1/12=2/11

35/4:5=35/4:5/1=35/4x1/5=7/4

=\(\dfrac{1}{6}\)

\(\dfrac{1}{6}\)

^{_{\(\dfrac{1}{6}\)}}