Question

Tính bằng cách hợp lý (nếu có)

a) ${A}= \dfrac{15}{12}+ \dfrac{5}{13}+ \dfrac{-3}{12}+ \dfrac{-18}{13}$

b) ${B}= \dfrac{11}{15} \cdot  \dfrac{-19}{13}+ \dfrac{-7}{13} \cdot  \dfrac{11}{15}$

c) ${C}=2022^{0}-\Big( \dfrac{1}{7}\Big)^5 \cdot 7^5$

Answer 1

a) A = 15/12 + 5/13 + (-3/12) + (-18/13)

= (15/12 - 3/12) + (5/13 - 18/13)

= 1 - 1

= 0

b) B = 11/15 . (-19/13) + (-7/13) . 11/15

= 11/15.(-19/13 - 7/13)

= 11/15 . (-2)

= -22/15

c) C = 2022⁰ - (1/7)⁵ . 7⁵

= 1 - 1/7⁵ . 7⁵

= 1 - 1

= 0

Answer 2

A = [15/12 + (-3/12)] + [5/13 + ( -18/13)]
A =  12/12 + ( -13/13) 

A = 1 + (-1)

A = 0

B = 11/15 x [(-19/13) + ( -7/13)]

B = 11/15 x (-26/13)

B = 11/15 x (-2)

B = -22/15

C = 1 - 1 mũ 5

C = 1 - 1

C = 0

 

 

 

Answer 3

A= 0

B= - 22/15

C= 0

Answer 4

a) \(A=\dfrac{15}{12}+\dfrac{5}{13}+\dfrac{-3}{12}+\dfrac{-18}{13}\)

        \(=\left(\dfrac{15}{12}+\dfrac{-3}{12}\right)+\left(\dfrac{5}{13}+\dfrac{-18}{13}\right)\)

        \(=\dfrac{12}{12}+\dfrac{-13}{13}\)

        \(=1+\left(-1\right)\)

        \(=0\)

b) \(B=\dfrac{11}{15}.\dfrac{-19}{13}+\dfrac{-7}{13}.\dfrac{11}{15}\)

        \(=\dfrac{11}{15}.\left(\dfrac{-19}{13}+\dfrac{-7}{13}\right)\)

        \(=\dfrac{11}{15}.\dfrac{-26}{13}\)

        \(=\dfrac{11}{15}.\left(-2\right)\)

        \(=\dfrac{-22}{15}\)

c) \(C=2022^0-\left(\dfrac{1}{7}\right)^5.7^5\)

        \(=1-\dfrac{1}{7^5}.7^5\)

        \(=1-1\)

        \(=0\)

Answer 5

a) A = 15/12 +5/13 + -3/12 + -18/13 

       = 15/12 - 3/12 + 5/13 - 18/13

       = 12/12 - 13/13 

       = 1 -1 =0

 

 

 

Answer 6

a) A= (\(\dfrac{15}{12}\)+\(\dfrac{-3}{12}\)) +(\(\dfrac{5}{13}\) +\(\dfrac{-18}{13}\))

A= 1+(-1)

A= 0

b) B=\(\dfrac{11}{15}\)  .(\(\dfrac{-19}{13}\) +\(\dfrac{-7}{13}\) )

B= \(\dfrac{11}{15}\) . -2

B= \(\dfrac{-22}{15}\)

c) C= 1- \(\dfrac{1}{16807}\) .16807

C= 1- 1

C= 0

Answer 7

a, A= 0

b, B=\(\dfrac{-22}{15}\)

c,C=0

 

Answer 8

11

Answer 9

a) A = 15/12 + 5/13 + -3/12 + -18/13

    A= 15/12 + -3/12 + 5/13 + -18/13

    A= 15/12 - 3/12 + 5/13 - 18/13

    A= 12/12 + -13/13

    A= 12/12 - 13/13

    A= 1 - 1

    A= 0

 

b)B= 11/15 . -19/13 + -7/13 . 11/15

   B= 11/15 . ( -19/13 + -7/13)

   B= 11/15 . (-19/13 - 7/13)

   B= 11/15 . -26/13

   B= 11/15 . -2

   B= -22/15

 

c)C= 2022⁰ - (1/7)⁵ . 7⁵

   C= 1 - 1/16807 . 16807

   C= 1 - 1

   C= 0

Answer 10

a) A = 15/12 + 5/13 + -3/12 + -18/13

    A = (15/12 + -3/12) + (5/13 + -18/13)

    A = 1 + -1

    A = 0

b) B = 11/15 . -19/13 + -7/13 . 11/15

    B = 11/15 . (-19/13 + -7/13)

    B = 11/15 . -2

    B = -22/15

c) C = 2022⁰ - (1/7)⁵ . 7⁵

    C = 1 - [(1/7) . 7)⁵

     C = 1 - (1)⁵

     C = 1 - 1

    C = 0