Question

Câu 13. Tính:

a) $\dfrac{5}{7} . \dfrac{5}{11}+\dfrac{5}{7} . \dfrac{6}{11}-\dfrac{5}{7} . \dfrac{4}{11}$;

b) $1,2-3^2+7,5$ $:$ $3$.

Answer 1

a

=5/7 * (5+6-4/11)

= 5/7+7/11

=5/11

b

=1,2 - 9 + 2,5

=  -7,8 + 2,5 

= -5,3

Answer 2

a

=5/7 * (5+6-4/11)

= 5/7+7/11

=5/11

b

=1,2 - 9 + 2,5

=  -7,8 + 2,5 

= -5,3

Answer 3

a, 5/7 * (5/11+6/11-4/11)

= 5/7* (-3/11) = -15/77

 

Answer 4

=5/7.(5/11+6/11-4/11)

=5/7.7/11

=35/11

=5/11

Answer 5

a.

5/7.5/11+5/7.6/11-5/7.4/11= 5/7.(5/11+6/11-4/11)=5/7.7/11=5/11

b.

1,2-3² +7,5:3 = 1,2 -9+2,5=-5,3 

Answer 6

a.

5/7.5/11+5/7.6/11-5/7.4/11=5/7. (5/11+6/11-4/11 )=5/7.7/11=5/11

b.

1,2-3² +7,5 :3 = 1,2 -9 +2,5 =-5,3

 

Answer 7

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Answer 8

a) \(\dfrac{5}{7}\cdot\dfrac{5}{11}+\dfrac{5}{7}\cdot\dfrac{6}{11}-\dfrac{5}{7}\cdot\dfrac{4}{11}\) 

\(=\dfrac{5}{7}\cdot\left(\dfrac{5}{11}+\dfrac{6}{11}-\dfrac{4}{11}\right)\)

\(=\dfrac{5}{7}\cdot\dfrac{7}{11}\)

\(=\dfrac{5}{11}\)

b) \(1,2-3^2+\dfrac{7,5}{3}\) 

\(=1,2-9+2,5\)

\(=-7,8+2,5\)

\(=-5,3\)

 

Answer 9

a 

Answer 10

a) 57.511+57.611−57.411=57.(511+611−411)=57.711=51175​.115​+75​.116​−75​.114​=75​.(115​+116​−114​)=75​.117​=115​;

b) 1,2−32+7,51,2−32+7,5 $:$ $3=1,2-9+2,5=-5,3$.

Answer 11

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Answer 12

a)\(\dfrac{5}{7}\)*\(\dfrac{5}{11}+\dfrac{5}{7}\)*\(\dfrac{6}{11}\)-\(\dfrac{5}{7}\)*\(\dfrac{4}{11}\)=\(\dfrac{5}{7}\)(\(\dfrac{5}{11}+\dfrac{6}{11}-\dfrac{4}{11}\))=\(\dfrac{5}{7}\)*\(\dfrac{7}{11}\)=\(\dfrac{5}{11}\)

b) 1,2−32+7,51,2−3\(^2\)
+7,5 $:$ $3$.=$1,2-9+2,5=-5,3$.

Answer 13

5\11

-5.3

 

Answer 14

a) 5/11

b) -5,3

 

Answer 15

a) 5/7 . 5/11 + 5/7 . 6/11 - 5/7 . 4/11

= 5/7 . (5/11 + 6/11 - 4/11)

= 5/7 . 7/11

= 5/11

b) 1,2 - 3² + 7,5 : 3

= 1,2 - 9 + 2,5

= -7,8 + 2,5

= -5,3

Answer 16

a) 5/7 . 5/11 + 5/7 . 6/11 - 5/7 . 4/11

= 5/7 . (5/11 + 6/11 - 4/11)

= 5/7 . 7/11

= 5/11

b) 1,2 - 3² + 7,5 : 3

= 1,2 - 9 + 2,5

= -7,8 + 2,5

= -5,3

Answer 17

a,25/77+30/77_20/77=35/77

b,1,2-9+2,5=-5,3