Question

Thực hiện phép tính (3 điểm).

a) $\dfrac{1}{2} \cdot \dfrac{4}{3}-\dfrac{20}{3} \cdot \dfrac{4}{5}$ ;

b) $\dfrac{3}{7}+\dfrac{-6}{19}+\dfrac{4}{7}+\dfrac{-13}{19}$ ;

c) $\dfrac{3}{5} \cdot \dfrac{8}{9}-\dfrac{7}{9} \cdot \dfrac{3}{5}+\dfrac{3}{5} \cdot \dfrac{26}{9}$.

Answer 1

Bài 1:

\(a,=\frac{2}{3}-\frac{16}{3}=\frac{-14}{3}\)

\(b,=\left(\frac{3}{7}+\frac{4}{7}\right)+\left(-\frac{6}{19}+\frac{-13}{19}\right)=1-1=0\)

\(c,=\frac{3}{5}.\left(\frac{8}{9}-\frac{7}{9}+\frac{26}{9}\right)=\frac{3}{5}.3=\frac{9}{5}\)

Answer 2

a,\(\dfrac{1}{2}\).\(\dfrac{4}{3}\)-\(\dfrac{20}{3}\).\(\dfrac{4}{5}\)=\(\dfrac{2}{3}\)-\(\dfrac{16}{3}\)=-\(\dfrac{14}{3}\)

Answer 3

                                           

                  

Answer 4

Answer 5

Answer 6

a 

Answer 7

2/3 - 16/3= -14/3

(3/4+4/7)+[(-6/19)+(-13/19)= 1+ (-1)=0

Answer 8

A,2/3-16/3=-14/3.

Answer 9

A,2/3-16/3=-14/3. B,(3/7+4/7)+(-6/19+-13/19)=1+(-1)=0. C,3/5×(8/9-7/9+26/9)=3/5×27/9=27/15

Answer 10

Answer 11

a)

Answer 12

a) 2/3 - 16/3 = -14/3

Answer 13

Answer 14

a=-14/3

B=0

C=9/5

Answer 15

a,2/3-16/3=-14/3

b,(3/7+4/7)+(-6/19+-13/19)=1+(-1)=0

c,3/5.(8/9-7/9+26/9)=3/5.3=9/5

Answer 16

Answer 17

) \dfrac{1}{2} \cdot \dfrac{4}{3}-\dfrac{20}{3} \cdot \dfrac{4}{5}21​⋅34​−320​⋅54​

=\dfrac{2}{3}-\dfrac{16}{3}=32​−316​

=-\dfrac{14}{3}=−314​ ;

b) \dfrac{3}{7}+\dfrac{-6}{19}+\dfrac{4}{7}+\dfrac{-13}{19}73​+19−6​+74​+19−13​

=\left( \dfrac{3}{7}+\dfrac{4}{7} \right)+\left( \dfrac{-6}{19}+\dfrac{-13}{19} \right)=(73​+74​)+(19−6​+19−13​)

=\dfrac{7}{7}+\dfrac{-19}{19}=77​+19−19​

$=1+\left(-1\right)=0$ ;

c) \dfrac{3}{5} \cdot \dfrac{8}{9}-\dfrac{7}{9} \cdot \dfrac{3}{5}+\dfrac{3}{5} \cdot \dfrac{26}{9}53​⋅98​−97​⋅53​+53​⋅926​

=\dfrac{3}{5} \cdot \left( \dfrac{8}{9}-\dfrac{7}{9}+\dfrac{26}{9} \right)=53​⋅(98​−97​+926​)

=\dfrac{3}{5} \cdot \dfrac{27}{9}=53​⋅927​

=\dfrac{3}{5} \cdot 3=53​⋅3

=\dfrac{9}{5}=59​.

Answer 18

a)\(\dfrac{2}{3}-\dfrac{16}{3}=\dfrac{-14}{3}\).

b)\(\left(\dfrac{3}{7}+\dfrac{4}{7}\right)+\left(\dfrac{-6}{19}+\dfrac{-13}{19}\right)=1+\left(-1\right)=0\)

c)\(\dfrac{3}{5}.\left(\dfrac{8}{9}-\dfrac{7}{9}+\dfrac{26}{9}\right)=\dfrac{3}{5}.3=\dfrac{9}{5}\)

Answer 19

 

 

 

 

 

 

a, 4/6 - 80/ 15 

=140/30 = 70/15 

Answer 20

M

Answer 21

Answer 22

Answer 23

a) \dfrac{1}{2} \cdot \dfrac{4}{3}-\dfrac{20}{3} \cdot \dfrac{4}{5}21​⋅34​−320​⋅
4​

=\dfrac{2}{3}-\dfrac{16}{32
316−314

Answer 24

A,=2/3-16/3

=-14/3

B, 

Answer 25

a) \dfrac{1}{2} \cdot \dfrac{4}{3}-\dfrac{20}{3} \cdot \dfrac{4}{5}21​⋅34​−320​⋅54​

=\dfrac{2}{3}-\dfrac{16}{3}=32​−316​

=-\dfrac{14}{3}=−314​ ;

b) \dfrac{3}{7}+\dfrac{-6}{19}+\dfrac{4}{7}+\dfrac{-13}{19}73​+19−6​+74​+19−13​

=\left( \dfrac{3}{7}+\dfrac{4}{7} \right)+\left( \dfrac{-6}{19}+\dfrac{-13}{19} \right)=(73​+74​)+(19−6​+19−13​)

=\dfrac{7}{7}+\dfrac{-19}{19}=77​+19−19​

$=1+\left(-1\right)=0$ ;

c) \dfrac{3}{5} \cdot \dfrac{8}{9}-\dfrac{7}{9} \cdot \dfrac{3}{5}+\dfrac{3}{5} \cdot \dfrac{26}{9}53​⋅98​−97​⋅53​+53​⋅926​

=\dfrac{3}{5} \cdot \left( \dfrac{8}{9}-\dfrac{7}{9}+\dfrac{26}{9} \right)=53​⋅(98​−97​+926​)

=\dfrac{3}{5} \cdot \dfrac{27}{9}=53​⋅927​

=\dfrac{3}{5} \cdot 3=53​⋅3

=\dfrac{9}{5}=59​.

Answer 26

Bài 1. (3 điểm) Thực hiện phép tính.

a) \dfrac{1}{2} \cdot \dfrac{4}{3}-\dfrac{20}{3} \cdot \dfrac{4}{5}21​⋅34​−320​⋅54​ ;

b) \dfrac{3}{7}+\dfrac{-6}{19}+\dfrac{4}{7}+\dfrac{-13}{19}73​+19−6​+74​+19−13​ ;

c) \dfrac{3}{5} \cdot \dfrac{8}{9}-\dfrac{7}{9} \cdot \dfrac{3}{5}+\dfrac{3}{5} \cdot \dfrac{26}{9}53​⋅98​−97​⋅53​+53​⋅926​.

Hướng dẫn giải:

a) \dfrac{1}{2} \cdot \dfrac{4}{3}-\dfrac{20}{3} \cdot \dfrac{4}{5}21​⋅34​−320​⋅54​

=\dfrac{2}{3}-\dfrac{16}{3}=32​−316​

=-\dfrac{14}{3}=−314​ ;

b) \dfrac{3}{7}+\dfrac{-6}{19}+\dfrac{4}{7}+\dfrac{-13}{19}73​+19−6​+74​+19−13​

=\left( \dfrac{3}{7}+\dfrac{4}{7} \right)+\left( \dfrac{-6}{19}+\dfrac{-13}{19} \right)=(73​+74​)+(19−6​+19−13​)

=\dfrac{7}{7}+\dfrac{-19}{19}=77​+19−19​

=1+\left( -1 \right)=0=1+(−1)=0 ;

c) \dfrac{3}{5} \cdot \dfrac{8}{9}-\dfrac{7}{9} \cdot \dfrac{3}{5}+\dfrac{3}{5} \cdot \dfrac{26}{9}53​⋅98​−97​⋅53​+53​⋅926​

=\dfrac{3}{5} \cdot \left( \dfrac{8}{9}-\dfrac{7}{9}+\dfrac{26}{9} \right)=53​⋅(98​−97​+926​)

=\dfrac{3}{5} \cdot \dfrac{27}{9}=53​⋅927​

=\dfrac{3}{5} \cdot 3=53​⋅3

=\dfrac{9}{5}=59​.

Answer 27

a) \dfrac{1}{2} \cdot \dfrac{4}{3}-\dfrac{20}{3} \cdot \dfrac{4}{5}21​⋅34​−320​⋅54​

=\dfrac{2}{3}-\dfrac{16}{3}=32​−316​

=-\dfrac{14}{3}=−314​ ;

b) \dfrac{3}{7}+\dfrac{-6}{19}+\dfrac{4}{7}+\dfrac{-13}{19}73​+19−6​+74​+19−13​

=\left( \dfrac{3}{7}+\dfrac{4}{7} \right)+\left( \dfrac{-6}{19}+\dfrac{-13}{19} \right)=(73​+74​)+(19−6​+19−13​)

=\dfrac{7}{7}+\dfrac{-19}{19}=77​+19−19​

$=1+\left(-1\right)=0$ ;

c) \dfrac{3}{5} \cdot \dfrac{8}{9}-\dfrac{7}{9} \cdot \dfrac{3}{5}+\dfrac{3}{5} \cdot \dfrac{26}{9}53​⋅98​−97​⋅53​+53​⋅926​

=\dfrac{3}{5} \cdot \left( \dfrac{8}{9}-\dfrac{7}{9}+\dfrac{26}{9} \right)=53​⋅(98​−97​+926​)

=\dfrac{3}{5} \cdot \dfrac{27}{9}=53​⋅927​

=\dfrac{3}{5} \cdot 3=53​⋅3

=\dfrac{9}{5}=59​.

Answer 28

A) -14/3 b) 0 c) 9/5

Answer 29

Answer 30