-5/7 . 2/11 + (-5/7) . 9/11 + 5/7

= -5/7 . 2/11 + -5/7 . 9/11 + (-5/7) . (-1)

= (-5/7) . (2/11 + 9/11 -1)

= (-5/7) . 0

=0

ks nha bạn

\(\frac{-5}{7}\times\frac{2}{11}+\frac{-5}{11}\times\frac{9}{11}+\frac{5}{7}\)

\(=\frac{-5}{7}\times\left(\frac{2}{11}+\frac{9}{11}\right)+\frac{5}{7}\)

\(=\frac{-5}{7}\times\frac{11}{11}+\frac{5}{7}\)

\(=\frac{-5}{7}\times1+\frac{5}{7}\)

\(=\frac{-5}{7}+\frac{5}{7}\)

\(=0\)

=105 nha 

băng  105

1+2+3+4+5+6+7+8+9+10+11+12+13+14=105

a: \(=\dfrac{1}{3}\cdot\dfrac{1}{3}\cdot\dfrac{-17}{18}\cdot\dfrac{14}{17}=\dfrac{-14}{18\cdot9}=\dfrac{-14}{162}=\dfrac{-7}{81}\)

b: \(=\dfrac{12}{4}+\dfrac{35}{11}\cdot\dfrac{121}{245}=3+\dfrac{11}{7}=\dfrac{32}{7}\)

a: \(=\dfrac{15}{135}\cdot\dfrac{-17}{18}\cdot\dfrac{14}{17}=\dfrac{1}{9}\cdot\dfrac{-7}{9}=\dfrac{-7}{81}\)

b: \(=3+\dfrac{35}{11}\cdot\dfrac{121}{245}=3+\dfrac{11}{7}=\dfrac{32}{7}\)

y=41/45

8/15

m=33/20

21/22 nhé

6/7

21/35 và 20/35 nhé

232/301

Gợi ý cho bn: Tách chúng ra nhé, rồi rút gọn số có ở trên cả tử và mẫu.

\(=\dfrac{2^{12}.3^{15}.7^{30}-31.2^{12}.3^{12}.3^2.7^{28}}{2^{11}.3^{14}.7^{14}.7^{15}+2^{12}.3^{15}.7^{30}}=\)

\(=\dfrac{2^{12}.3^{15}.7^{30}-31.2^{12}.3^{14}.7^{28}}{2^{11}.3^{14}.7^{29}+2^{12}.3^{15}.7^{30}}=\)

\(=\dfrac{2^{11}.3^{14}.7^{28}\left(2.3.7^2-31.2\right)}{2^{11}.3^{14}.7^{28}\left(7+2.3\right)}=\dfrac{2.3.7^2-31.2}{7+2.3}=\dfrac{232}{13}\)

\(\dfrac{5}{11}+\dfrac{4}{11}=\dfrac{9}{11}\\ \dfrac{11}{10}+\dfrac{9}{10}=\dfrac{20}{10}=2\\ \dfrac{11}{12}+\dfrac{5}{12}=\dfrac{16}{12}=\dfrac{4}{3}\\ \dfrac{7}{9}+\dfrac{5}{9}=\dfrac{12}{9}=\dfrac{4}{3}\)

\(\dfrac{5}{11}+\dfrac{4}{11}=1\)

\(\dfrac{11}{10}+\dfrac{9}{10}=\dfrac{20}{10}=2\)

\(\dfrac{11}{12}+\dfrac{5}{12}=\dfrac{16}{12}=\dfrac{4}{3}\)

\(\dfrac{7}{9}+\dfrac{5}{9}=\dfrac{12}{9}=\dfrac{4}{3}\)

5/11+4/11=9/11

11/10+9/10=20/10=2

11/12+5/12=16/12=4/3

7/9+5/9=12/9=4/3 nhé =)

a= -1/7

b -50/21

c   1/8

d 19/56

e-13/24

f -89/312