Question

Thực hiện phép tính một cách hợp lí (nếu có thể):

a) $\dfrac{5}{9}-{{\Big(\dfrac{1}{3} \Big)}^{2}}$                   

b)$\dfrac{1}{5}. \dfrac{-3}{2}+\dfrac{-17}{2}. \dfrac{1}{5}$        

c) $1+\Big(\dfrac{-2}{5}+\dfrac{11}{13} \Big)-\Big(\dfrac{3}{5}-\dfrac{2}{13} \Big)$

Answer 1

`a) 5/9 - (1/3)^2= 5/9- 1/9= 4/9`

`b) 1/5. -3/2 + -17/2. 1/5= 1/5. (-3/2+-17/2)= 1/5.(-10)= -2`

`c) 1+ (-2/5 + 11/13) - (3/5- 2/13)= 1+ -2/5 + 11/13 + -3/5 + 2/13= 1+ (-2/5+ -3/5) +  (11/13+2/13) =1+ (-1)+1=1`

Answer 2

A,=5/9-1/9

=4/9

B1/5.-3/2+-17/2.1/5

=1/5.[-3/2+(-17/2)]

=-10/2

C,=1+(-2/5-3/5)+(11/13+2/13)

1+(-1)+1

=1

Answer 3

A,=5/9-1/9

=4/9

B1/5.-3/2+-17/2.1/5

=1/5.[-3/2+(-17/2)]

=-10/2

C,=1+(-2/5-3/5)+(11/13+2/13)

1+(-1)+1

=1

Answer 4

A=4/9.   B=7/5.  C=1

Answer 5

a)4/9  b)-2  c)1

 

Answer 6

a) 4/9 b)-2 c)1

Answer 7

a,2/9

b,-2

c,1

Answer 8

\(\dfrac{ }{ }\)

Answer 9

a) 4/9  

b)-2

c) 1

Answer 10

a)5/9-(1/3)^2=4/

b)1/5×-3/2+-17/2×1/5=-2

c)1+(-2/5+11/13)-(3/5-2/13=1

Answer 11

a)5/9-(1/3)² =

 

Answer 12

ưdawda ưdaw

Answer 13

 

a) 59−(13)2=59−19=4995​−(31​)2=95​−91​=94​

b) 15. −32+−172. 1551​. 2−3​+2−17​. 51​

=15.(−32+−172)=51​.(2−3​+2−17​)

=15.(−10)=−2=51​.(−10)=−2

c) 1+(−25+1113)−(35−213)1+(5−2​+1311​)−(53​−132​)

=1+−25+1113−35+213=1+5−2​+1311​−53​+132​

=1+(−25−35)+(1113+213)=1+(5−2​−53​)+(1311​+132​)

$=1+(-1)+1=1$

 

=1+(−1)+1=1

 

Answer 14

a,4/9 b,-2 c,1

Answer 15

a,5/9 -(1/3)^2

=5/9 -1/9

=4/9

b,1/5.-3/2+-17/2.1/5

=1/5.(-3/2-17/2)

=1/5.(-20/2)=1/5.(-10)=10/5=2

c,1+(-2/5+11/13)-(3/5-2/13)

=1-2/5+11/3-3/5+2/3

=1+(-2/5-3/5)+(11/13+2/13)=1+(-1)+1=1

Answer 16

a, 4/9

b, -2

c, 1

 

Answer 17

a. 5/9-(1/3)²=5/9-1/9=4/9

b. 1/5.-3/2+-17/2.1/5 = 1/5. (-3/2+-17/2) = 1/5.-10 = 2

c. 1+(-2/5+11/13)-(3/5-2/13) = 1+-2/5+11/13-3/5+2/13 = 1+(-2/5-3/5)+(11/13+2/13) = 1+(-1)+1=1

Answer 18

a)\(\dfrac{5}{9}-\left(\dfrac{1}{9}\right)=\dfrac{5-1}{9}=\dfrac{4}{9}\)

b)\(\dfrac{1}{5}.\left(\dfrac{-3}{2}+\dfrac{-17}{2}\right)=\dfrac{1}{5}.\left(-10\right)=-2\)

c)\(1+\dfrac{29}{65}-\dfrac{29}{65}=\dfrac{94}{65}-\dfrac{29}{65}=1\)

Answer 19

a)5/9-(1/9)=4/9

b)1/5.(-3/2+-17/2)=1/5.(-10)=-2

c)1+(-2/5+11/13)-(3/5-2/13)=1+(-2/5)+11/13-(-3/5)+2/13

4/5=1

Answer 20

a,4/9

b,-2

c,1

Answer 21

a,\(\dfrac{4}{9}\) 

b,-2

c,1

Answer 22

a,5/9-(1/3)^2=5/9-1/9=4/9

b,1/5.-3/2+-17/2.1/5=1/5.(-3/2+-17/2)=1/5.-10=-2

c,1+(-2/5+11/13)-(3/5-2/13)=1+-2/5+11/13-3/5+2/13=1+(-2/5-3/5)+(11/13+2/13)=1+-1+1=1

 

Answer 23

a) 5/9 - (1/3)² = 5/9 - 1/9 = 4/9

b) 1/5 . -3/2 + -17/2 . 1/5 = 1/5.(-3/2 + -17/2) = 1/5 . -20/2 = 1/5 . -10 = -10/5 = -2

c) 1 + (-2/5 + 11/13) - (3/5 - 2/13) = 1 + (-2/5) + 11/13 - 3/5 + 2/13 = 1 + (-2/5 - 3/5) + (11/13 + 2/13) = 1 + (-1) + 1 = 1

Answer 24

c)1

 

a)4/9

b)2

 

 

Answer 25

`a) 5/9 - (1/3)^2= 5/9- 1/9= 4/9`

`b) 1/5. -3/2 + -17/2. 1/5= 1/5. (-3/2+-17/2)= 1/5.(-10)= -2`

`c) 1+ (-2/5 + 11/13) - (3/5- 2/13)= 1+ -2/5 + 11/13 + -3/5 + 2/13= 1+ (-2/5+ -3/5) +  (11/13+2/13) =1+ (-1)+1=1`

Answer 26

A, 4/9

B,-2

C,1

Answer 27

5/9-1/3^2

=5/9-1/9

=4/9

Answer 28

a) 5/9 - (1/3)^{2                  b)1/5 . -3/2 + -17/2 . 1/5                  c) 1+ (-2/5+11/13) - (3/5 - 2/13)}

^{= 5/9 - 1/9                            = 1/5 . (-3/2 - 17/2)                          = 1+ (-2/5) + 11/13 - 3/5 + 2/13}

^{= 4/9                                     = 1/5 . (-10)                                     = 1+(-2/5-3/5) + ( 11/13 + 2/13)}

                                             ^{= -2                                                  = 1+ (-1) +1}

                                                                                                      ^{= 1}

Answer 29

 

 

 

 

 

Answer 30

4/9;