Question

Tính giá trí của biểu thức sau theo cách hợp lí nhất.
a) $\mathrm{A}=\dfrac{3}{5} \cdot \dfrac{6}{7}+\dfrac{3}{7}: \dfrac{5}{3}-\dfrac{2}{7}: 1 \dfrac{2}{3}$;
b) $\mathrm{B}=\left(-13 \cdot \dfrac{2}{5}+\dfrac{-2}{9}: 2 \dfrac{1}{2}+\dfrac{2}{5}. \dfrac{11}{9}\right) \cdot 2 \dfrac{1}{2}$;
c) $\mathrm{C}=\left(\dfrac{-4}{5}+\dfrac{5}{7}\right): \dfrac{2}{3}+\left(\dfrac{-1}{5}+\dfrac{2}{7}\right): \dfrac{2}{3}$;
d) $\mathrm{D}=\dfrac{4}{9}:\left(\dfrac{1}{15}-\dfrac{2}{3}\right)+\dfrac{4}{9}:\left(\dfrac{1}{11}-\dfrac{5}{22}\right)$.

Answer 1

Answer 2

A= 3/5.6/7+3/5.3/7-3/5.2/7

A= 3/5. (6/7+3/7-2/7) = 3/5

B= (-13.2/5+-2/9.2/5+2/5.11/9).5/2

B= (-13-2/9+11/9).2/5.5/2

B= -13+(11/9-2/9)= -12

C= (-4/5+5/7).3/2+(-1/5+2/7).3/2

C= (-4/5+5/7+-1/5+2/7).3/2

C= ((-4/5+-1/5)+(5/7+2/7)).3/2

C= 0

D= 4/9.-5/3+4/9.-22/3

D= 4/9.110/9

D= 440/81

Answer 3

.

Answer 4

a) \mathrm{A}=\dfrac{3}{5}. \dfrac{6}{7}+\dfrac{3}{7}. \dfrac{3}{5}-\dfrac{2}{7}. \dfrac{3}{5}A=53​. 76​+73​. 53​−72​. 53​

b)  \mathrm{B} =\left(-13 \cdot \dfrac{2}{5}+\dfrac{-2}{9} \cdot \dfrac{2}{5}+\dfrac{2}{5} \cdot \dfrac{11}{9}\right) \cdot \dfrac{5}{2} B=(−13⋅52​+9−2​⋅52​+52​⋅911​)⋅25​
=\left(-13-\dfrac{2}{9}+\dfrac{11}{9}\right) \cdot \dfrac{2}{5} \cdot \dfrac{5}{2}=-13+\left(\dfrac{11}{9}-\dfrac{2}{9}\right)=-12 .=(−13−92​+911​)⋅52​⋅25​=−13+(911​−92​)=−12.
c) \mathrm{C} =\left(\dfrac{-4}{5}+\dfrac{5}{7}\right) \cdot \dfrac{3}{2}+\left(\dfrac{-1}{5}+\dfrac{2}{7}\right) \cdot \dfrac{3}{2} =\left(\dfrac{-4}{5}+\dfrac{5}{7}+\dfrac{-1}{5}+\dfrac{2}{7}\right) \cdot \dfrac{3}{2}=\left(\left(\dfrac{-4}{5}+\dfrac{-1}{5}\right)+\left(\dfrac{5}{7}+\dfrac{2}{7}\right)\right) \cdot \dfrac{3}{2}=0 .C=(5−4​+75​)⋅23​+(5−1​+72​)⋅23​=(5−4

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Answer 5

A=3/5.6/7+3/7.3/5-2/7.3/5

A=3/5.(6/7+3/7-2/7)

A= 3/5.1

A=3/5

B =(-13.2/5+-2/9.2/5+11/9.2/5).5/2

B = 9-13-2/9+11/9).2/5.5/2

B = -13+(11/9-2/9)

B=-12

C=(-4/5+5/7).3/2+(-1/5+2/7).3/2

C = -4/5+5/7+-1/5+2/7).3/2

C = (-4/5+-1/5)+(5/7+2/7).3/2

C =-1+1.3/2

C =0

D =4/9:(1/15-10/15)+4/9:(2/22-5/22)

D = 4/9:-3/5+4/9:-3/22

D = 4/9.(-5/3+-22/3)

D=4/9.-27/3

D=-4

Answer 6

a) \(A=\dfrac{3}{5}.\dfrac{6}{7}+\dfrac{3}{7}.\dfrac{3}{5}-\dfrac{2}{7}.\dfrac{3}{5}\)

    \(A=\dfrac{3}{5}.\dfrac{6}{7}+\dfrac{3}{5}.\dfrac{3}{7}-\dfrac{2}{7}.\dfrac{3}{5}\)

    \(A=\dfrac{3}{5}.\left(\dfrac{6}{7}+\dfrac{3}{7}-\dfrac{2}{7}\right)\)

    \(A=\dfrac{3}{5}.1\)

    \(A=\dfrac{3}{5}\)

b) \(B=\left(-13.\dfrac{2}{5}+\dfrac{-2}{9}:2\dfrac{1}{2}+\dfrac{2}{5}.\dfrac{11}{9}\right).2\dfrac{1}{2}\)

    \(B=\left(-13.\dfrac{2}{5}+\dfrac{-2}{9}:\dfrac{5}{2}+\dfrac{2}{5}.\dfrac{11}{9}\right).\dfrac{5}{2}\)

    \(B=\left(-13.\dfrac{2}{5}+\dfrac{-2}{9}.\dfrac{5}{2}+\dfrac{2}{5}.\dfrac{11}{9}\right).\dfrac{5}{2}\)

    \(B=\left(-13+\dfrac{-2}{9}+\dfrac{11}{9}\right).\dfrac{2}{5}.\dfrac{5}{2}\)

    \(B=-13+\left(\dfrac{-2}{9}+\dfrac{11}{9}\right)\)

    \(B=-13+1\)

    \(B=-12\)

c) \(C=\left(\dfrac{-4}{5}+\dfrac{5}{7}\right):\dfrac{2}{3}+\left(\dfrac{-1}{5}-\dfrac{2}{7}\right):\dfrac{2}{3}\)

    \(C=\left(\dfrac{-4}{5}+\dfrac{5}{7}\right).\dfrac{3}{2}+\left(\dfrac{-1}{5}-\dfrac{2}{7}\right).\dfrac{3}{2}\)

    \(C=\left(\dfrac{-4}{5}+\dfrac{5}{7}+\dfrac{-1}{5}-\dfrac{2}{7}\right).\dfrac{3}{2}\)

    \(C=\left(\dfrac{-4}{5}+\dfrac{-1}{5}+\dfrac{5}{7}+\dfrac{2}{7}\right).\dfrac{3}{2}\)

    \(C=\left(-1+1\right).\dfrac{3}{2}\)

    \(C=0\)

    d) \(D=\dfrac{4}{9}:\left(\dfrac{1}{15}-\dfrac{2}{3}\right)+\dfrac{4}{9}:\left(\dfrac{1}{11}-\dfrac{5}{22}\right)\)

         \(D=\dfrac{4}{9}:\left(\dfrac{1}{15}-\dfrac{10}{15}\right)+\dfrac{4}{9}:\left(\dfrac{2}{22}-\dfrac{5}{22}\right)\)

         \(D=\dfrac{4}{9}:\dfrac{-3}{5}+\dfrac{4}{9}:\dfrac{-3}{22}\)

         \(D=\dfrac{4}{9}.\dfrac{-5}{3}+\dfrac{4}{9}.\dfrac{-22}{3}\)

         \(D=\dfrac{4}{9}.\left(\dfrac{-5}{3}+\dfrac{-22}{3}\right)\)

         \(D=\dfrac{4}{9}.\left(-9\right)\)

         \(D=-4\)

Answer 7

a) \(A=\dfrac{3}{5}.\dfrac{6}{7}+\dfrac{3}{7}.\dfrac{3}{5}-\dfrac{2}{7}.\dfrac{3}{5}\)

    \(A=\dfrac{3}{5}.\dfrac{6}{7}+\dfrac{3}{5}.\dfrac{3}{7}-\dfrac{2}{7}.\dfrac{3}{5}\)

    \(A=\dfrac{3}{5}.\left(\dfrac{6}{7}+\dfrac{3}{7}-\dfrac{2}{7}\right)\)

    \(A=\dfrac{3}{5}.1\)

    \(A=\dfrac{3}{5}\)

b) \(B=\left(-13.\dfrac{2}{5}+\dfrac{-2}{9}:2\dfrac{1}{2}+\dfrac{2}{5}.\dfrac{11}{9}\right).2\dfrac{1}{2}\)

    \(B=\left(-13.\dfrac{2}{5}+\dfrac{-2}{9}:\dfrac{5}{2}+\dfrac{2}{5}.\dfrac{11}{9}\right).\dfrac{5}{2}\)

    \(B=\left(-13.\dfrac{2}{5}+\dfrac{-2}{9}.\dfrac{5}{2}+\dfrac{2}{5}.\dfrac{11}{9}\right).\dfrac{5}{2}\)

    \(B=\left(-13+\dfrac{-2}{9}+\dfrac{11}{9}\right).\dfrac{2}{5}.\dfrac{5}{2}\)

    \(B=-13+\left(\dfrac{-2}{9}+\dfrac{11}{9}\right)\)

    \(B=-13+1\)

    \(B=-12\)

c) \(C=\left(\dfrac{-4}{5}+\dfrac{5}{7}\right):\dfrac{2}{3}+\left(\dfrac{-1}{5}-\dfrac{2}{7}\right):\dfrac{2}{3}\)

    \(C=\left(\dfrac{-4}{5}+\dfrac{5}{7}\right).\dfrac{3}{2}+\left(\dfrac{-1}{5}-\dfrac{2}{7}\right).\dfrac{3}{2}\)

    \(C=\left(\dfrac{-4}{5}+\dfrac{5}{7}+\dfrac{-1}{5}-\dfrac{2}{7}\right).\dfrac{3}{2}\)

    \(C=\left(\dfrac{-4}{5}+\dfrac{-1}{5}+\dfrac{5}{7}+\dfrac{2}{7}\right).\dfrac{3}{2}\)

    \(C=\left(-1+1\right).\dfrac{3}{2}\)

    \(C=0.\dfrac{3}{2}\)

    \(C=0\)

d) \(D=\dfrac{4}{9}:\left(\dfrac{1}{15}-\dfrac{2}{3}\right)+\dfrac{4}{9}:\left(\dfrac{1}{11}-\dfrac{5}{22}\right)\)

     \(D=\dfrac{4}{9}:\left(\dfrac{1}{15}-\dfrac{10}{15}\right)+\dfrac{4}{9}:\left(\dfrac{2}{22}-\dfrac{5}{22}\right)\)

     \(D=\dfrac{4}{9}:\dfrac{-3}{5}+\dfrac{4}{9}:\dfrac{-3}{22}\)

     \(D=\dfrac{4}{9}.\dfrac{-5}{3}+\dfrac{4}{9}.\dfrac{-22}{3}\)

     \(D=\dfrac{4}{9}.\left(\dfrac{-5}{3}+\dfrac{-22}{3}\right)\)

     \(D=\dfrac{4}{9}.\left(-9\right)\)

     \(D=-4\)

Answer 8

a) \mathrm{A}=\dfrac{3}{5}. \dfrac{6}{7}+\dfrac{3}{7}. \dfrac{3}{5}-\dfrac{2}{7}. \dfrac{3}{5}A=53​. 76​+73​. 53​−72​. 53​
=\dfrac{3}{5} \cdot\left(\dfrac{6}{7}+\dfrac{3}{7}-\dfrac{2}{7}\right)=\dfrac{3}{5}=53​⋅(76​+73​−72​)=53​
b)  \mathrm{B} =\left(-13 \cdot \dfrac{2}{5}+\dfrac{-2}{9} \cdot \dfrac{2}{5}+\dfrac{2}{5} \cdot \dfrac{11}{9}\right) \cdot \dfrac{5}{2} B=(−13⋅52​+9−2​⋅52​+52​⋅911​)⋅25​
=\left(-13-\dfrac{2}{9}+\dfrac{11}{9}\right) \cdot \dfrac{2}{5} \cdot \dfrac{5}{2}=-13+\left(\dfrac{11}{9}-\dfrac{2}{9}\right)=-12 .=(−13−92​+911​)⋅52​⋅25​=−13+(911​−92​)=−12.
c) \mathrm{C} =\left(\dfrac{-4}{5}+\dfrac{5}{7}\right) \cdot \dfrac{3}{2}+\left(\dfrac{-1}{5}+\dfrac{2}{7}\right) \cdot \dfrac{3}{2} =\left(\dfrac{-4}{5}+\dfrac{5}{7}+\dfrac{-1}{5}+\dfrac{2}{7}\right) \cdot \dfrac{3}{2}=\left(\left(\dfrac{-4}{5}+\dfrac{-1}{5}\right)+\left(\dfrac{5}{7}+\dfrac{2}{7}\right)\right) \cdot \dfrac{3}{2}=0 .C=(5−4​+

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Answer 9

A =3/5
B = -12
C = 0
D = -4

Answer 10

Answer 11

a) \(A=\dfrac{3}{5}.\dfrac{6}{7}+\dfrac{3}{7}:\dfrac{5}{3}-\dfrac{2}{7}:1\dfrac{2}{3}\)

\(A=\dfrac{3}{5}.\dfrac{6}{7}+\dfrac{3}{7}:\dfrac{5}{3}-\dfrac{2}{7}:\dfrac{5}{3}\)

\(A=\left(\dfrac{3}{5}.\dfrac{5}{3}:\dfrac{5}{3}\right):\left(\dfrac{6}{7}+\dfrac{3}{7}-\dfrac{2}{7}\right)\)

\(A=\left(1.\dfrac{3}{5}\right):1\)

\(A=\dfrac{3}{5}:1\)

\(A=\dfrac{3}{5}\)

c) \(C=\left(\dfrac{-4}{5}+\dfrac{5}{7}\right):\dfrac{2}{3}+\left(\dfrac{-1}{5}+\dfrac{2}{7}\right):\dfrac{2}{3}\)

\(C=\dfrac{-4}{5}+\dfrac{5}{7}:\dfrac{2}{3}+\dfrac{-1}{5}+\dfrac{2}{7}:\dfrac{2}{3}\)

\(C=\left[\left(\dfrac{-4}{5}\right)+\left(\dfrac{-1}{5}\right)\right]:\left(\dfrac{2}{3}:\dfrac{2}{3}\right)+\left(\dfrac{5}{7}+\dfrac{2}{7}\right)\)

\(C=\left(-1\right):1+1\)

\(C=0\)

 

Answer 12

\(a,A=\dfrac{3}{5}.\dfrac{6}{7}+\dfrac{3}{7}:\dfrac{5}{3}-\dfrac{2}{7}:1\dfrac{2}{3}\)

\(=\dfrac{3}{5}.\left(\dfrac{6}{7}+\dfrac{3}{7}-\dfrac{2}{7}\right)\)

\(=\dfrac{3}{5}\)

\(b,B=(-13.\dfrac{2}{5}+\dfrac{-2}{9}.\dfrac{2}{5}+\dfrac{2}{5}.\dfrac{11}{9}).\dfrac{5}{2}\)

\(=(-13-\dfrac{2}{9}+\dfrac{11}{9}).\dfrac{2}{5}.\dfrac{5}{2}\)

\(=-13+(\dfrac{11}{9}-\dfrac{2}{9})\)

\(=-13+(\dfrac{11}{9}-\dfrac{2}{9})\)

\(=-12\)

\(c,C=(\dfrac{-4}{5}+\dfrac{5}{7}).\dfrac{3}{2}+(\dfrac{-1}{5}+\dfrac{2}{7}).\dfrac{3}{2}\)

\(=(\dfrac{-4}{5}+\dfrac{5}{7}+\dfrac{-1}{5}+\dfrac{2}{7}).\dfrac{3}{2}\)

\(=[(\dfrac{-4}{5}+\dfrac{-1}{5})+(\dfrac{5}{7}+\dfrac{2}{7})].\dfrac{3}{2}\)

\(=0\)

\(d,D=\dfrac{4}{9}:(\dfrac{1}{15}-\dfrac{10}{15})+\dfrac{4}{9}:(\dfrac{2}{22}-\dfrac{5}{22})\)

\(=\dfrac{4}{9}:\dfrac{-3}{5}+\dfrac{4}{9}:\dfrac{-3}{22}\)

\(=\dfrac{4}{9}.\dfrac{-5}{3}+\dfrac{4}{9}.\dfrac{-22}{3}\)

\(=\dfrac{4}{9}.(\dfrac{-5}{3}+\dfrac{-22}{3})\)

\(=\dfrac{4}{9}.\dfrac{-27}{3}\)

\(=-4\)

Answer 13

a) A = \(\dfrac{3}{5}\) . \(\dfrac{6}{7}\) + \(\dfrac{3}{7}\) : \(\dfrac{5}{3}\) - \(\dfrac{2}{7}\) : 1\(\dfrac{2}{3}\) = \(\dfrac{3}{5}\) . \(\dfrac{6}{7}\) + \(\dfrac{3}{7}\) . \(\dfrac{3}{5}\) - \(\dfrac{2}{7}\) . \(\dfrac{3}{5}\) 

                                                  = \(\dfrac{3}{5}\) . ( \(\dfrac{6}{7}\) + \(\dfrac{3}{7}-\dfrac{2}{7}\) ) = \(\dfrac{3}{5}\) 

b) B = ( \(-13.\dfrac{2}{5}\) + \(\dfrac{-2}{9}\) : 2\(\dfrac{1}{2}\) + \(\dfrac{2}{5}\) . \(\dfrac{11}{9}\) ) . 2\(\dfrac{1}{2}\) 

 

Answer 14

a, A = \(\dfrac{3}{5}.\dfrac{6}{7}+\dfrac{3}{7}.\dfrac{3}{5}-\dfrac{2}{7}.\dfrac{3}{5}\)

= \(\dfrac{3}{5}.\left(\dfrac{6}{7}+\dfrac{3}{7}-\dfrac{2}{7}\right)\)

= \(\dfrac{3}{5}\)

b, B = ( - 13 . \(\dfrac{2}{5}+\dfrac{-2}{9}.\dfrac{2}{5}+\dfrac{2}{5}.\dfrac{11}{9}\) ) . \(\dfrac{5}{2}\)

= ( - 13 - \(\dfrac{2}{9}\) + \(\dfrac{11}{9}\) ) . \(\dfrac{2}{5}.\dfrac{5}{2}\)

= - 13 + \(\left(\dfrac{11}{9}-\dfrac{2}{9}\right)\)

= - 12 

c, \(\left(\dfrac{-4}{5}+\dfrac{5}{7}\right).\dfrac{3}{2}+\left(\dfrac{-1}{5}+\dfrac{2}{7}\right).\dfrac{3}{2}\)

= \(\left(\dfrac{-4}{5}+\dfrac{5}{7}+\dfrac{-1}{5}+\dfrac{2}{7}\right).\dfrac{3}{2}\)

= \(\left(\left(\dfrac{-4}{5}+\dfrac{-1}{5}\right)+\left(\dfrac{5}{7}+\dfrac{2}{7}\right)\right)\) . \(\dfrac{3}{2}\)

= 0

d, D = \(\dfrac{4}{9}:\left(\dfrac{1}{15}-\dfrac{10}{15}\right)+\dfrac{4}{9}:\left(\dfrac{2}{22}-\dfrac{5}{22}\right)\)

= \(\dfrac{4}{9}:\dfrac{-3}{5}+\dfrac{4}{9}:\dfrac{-3}{22}=\dfrac{4}{9}.\dfrac{-5}{3}+\dfrac{4}{9}.\dfrac{-22}{3}\)

= \(\dfrac{4}{9}.\left(\dfrac{-5}{3}+\dfrac{-22}{3}\right)=\dfrac{4}{9}.\dfrac{-27}{3}=-4\)

Answer 15

7\6

+

Answer 16

A = 3/5 . 6/7 + 3/7 : 5/3 - 2/7 : 1(2/3)

A = 3/5 . ( 6/7 + 3/7 - 2/7 ) : ( 5/3 : 5/3 )

A = 3/5 . 1 : 1 

A = 3/5

B = ( -13 . 2/5 + -2/9 : 2(1/2) + 2/5 . 11/9 ). 2(1/2)

B = -13 . ( 2/5 : 2/5 ) + ( -2/9 + 11/9 ) . ( 5/2 . 5/2 )

B = -13 . 1 + 1 . 5

B = -13 + 5

B = -8

C = ( -4/5 + 5/7 ) : 2/3 + ( -1/5 + 2/7 ) : 2/3

C = 3/2 . [( -4/5 + -1/5 )+( 5/7 + 2/7 )] 

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

C = 3/2 . 0

C = 0

D = 4/9 : ( 1/15 - 2/3 ) + 4/9 : ( 1/11 - 5/22 )

D = 4/9 . ( -5/3 + -22/3 )

D = 4/9 . (-9)

D = -4

Answer 17

Answer 18

      

Answer 19

Bước làm:

Bước 1: Đưa số hữu tỉ về dạng phân số.

Bước 2: Đưa phép chia về dạng phép nhân các phân số.

Bước 3: Áp dụng tính chất của phép nhân các phân số: Bao gồm giao hoán, kết hợp, phân phối với phép cộng (trừ).

 

Answer 20

Answer 21

a) A= 3/5

b) B=-12

c) C =0

d) D=-4

 

Answer 22

A) 3/5

B) -12

C) 0

D) -4

Answer 23

a) A = 3/5 . 6/7 + 3/7 : 5/3 - 2/7 : 1/ 2/3

=3/5.(6/7+3/7-2/7)=3/5

b,B=(-13.2/5+-2/9.2/5+2/5.11/9).5/2

=(-13.2/5+11/9).2/5.5/2

=-13+(11/9-2/9)

=-12

c,C=(-4/5+5/7).3/2+(-1/5+2/7).3/2

=(-4/5+5/7+-1/5+2/7).3/2

=(-4/5+-1/5)+(5/7+2/7).3/2=0

 

Answer 24

3/5.6/7+3/7:5/3-2/7:1.2/3

=3/5.6/7+3/7.3/5-2/7:5/3

=3/5.6/7+3/7-3/5-2/7.3/5

3/5(6/7+3/7-2/7)

=3/5.1=3/5

B=(-13.2/5+-2/9:2.1/2+2/5.11/9).2.1/2

=(-13.2/5+-2/9:5/2+2/5.11/9).5/2

(2/5(-13-2/9+11/9)).5/2

2/5.(-12).5/2

=-12

C=(-4/5+5/7):2/3+(-1/5+2/7);2/3

=(-4/5+5/7-1/5+2/7):2/3

=((-4/5-1/5)+(5/7+2/7));2/3

=(-1+1):2/3

=0:2/3

=0

D=4/9:(1/15-2/3)+4/9:(1/11-5/22)

=4/9:(1/15-10/15)+4/9:(2/22-5/22)

=4/9.(15/-9)+4/9:(-3/22)

=4/9.(15/-9)+4/9.(22/-3)

=-20/27+(88/27)=-4

Answer 25

A= 3/5 . 6/7 + 3/7 : 5/3 - 2/7 : 1 2/3 = 3/5 . (6/7 + 3/7 - 2/7) = 3/5

B=( -13 . 2/5 + -2/9 : 2 1/2  + 2/5 .11/9) . 2 1/2=(-13 -2/9 + 11/9) . 2/5 . 5/2=-13 + (11/9 - 2/9)= -12

C=(-4/5 + 5/7) : 2/3 + (-1/5 + 2/7) : 2/3 = -4/5 + 5/7. 3/2 + -1/5 + 2/7.3/2 = 3/2 . (-4/5 + -1/5) + (5/7 + 2/7)= 3/2 :(-1) + 1 = -2/3 + 1 = -1/2

D=4/9 : (1/15 - 2/3) + 4/9 : (1/11 - 5/22) = 4/9 : -3/5 + 4/9 : -3/22 = 4/9 . -5/3 + 4/9 . -22/3 = 4/9 . -5/3 + -22/3 = 4/9 . (-5/3 + -22/3) = 4/9 . -27/3 = -4

Answer 26

A=3/7

B=-12

C=0

D=-4

Answer 27

A=3/3 , B=-216/87 , C=1/2 , D =-399/440

 

Answer 28

Answer 29

a)A= \(\dfrac{3}{5}\)

b)B=-14

c) C = 0

d) D = \(\dfrac{440}{729}\)

Answer 30

a) A=35. 67+37. 35−27. 35A=53​. 76​+73​. 53​−72​. 53​
=35⋅(67+37−27)=35=53​⋅(76​+73​−72​)=53​
b)  B=(−13⋅25+−29⋅25+25⋅119)⋅52 B=(−13⋅52​+9−2​⋅52​+52​⋅911​)⋅25​
=(−13−29+119)⋅25⋅52=−13+(119−29)=−12.=(−13−92​+911​)⋅52​⋅25​=−13+(911​−92​)=−12.
c) C=(−45+57)⋅32+(−15+27)⋅32=(−45+57+−15+27)⋅32=((−45+−15)+(57+27))⋅32=0.C=(5−4​+75​)⋅

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