Question

Tính (một cách hợp lí) :

a) \(18.17-3.6.7\)

b) \(54-6.\left(17+9\right)\)

c) \(33.\left(17-5\right)-17.\left(33-5\right)\)

Answer 1

a)

b)

c)

Answer 2

a) 18.17 - 3.6.7

= 18.17 - 18.7

= 18.(17 - 7 )

= 18 . 10

= 180

b) 54 - 6.(17 + 9)

= 6.9 - 6.17 + 6.9

= (6.9 - 6.9) - 6.17

= 0 - 6.17

= 0 - 102

= -102

c) 33.(17 - 5) - 17.(33 - 5)

= 33.17 - 33.5 - 17 . 33 - 17.5

= 33.(17 - 17) - 5.(33 - 17 )

= 33. 0 - 5.16

= 0 - 80

= -80

Answer 3

a, 18.17 - 3.6.7 = 18.17 - 18.7

= 18 ( 17 - 7 )

= 18 . 10

= 180

b, 54 - 6( 17 + 9 ) = 6.9 - 6 ( 17 + 9 )

= 6 ( 9-17-9 )

= 6 . (-17 )

= -102

c, 33.(17-5 ) -17 ( 33-5 ) = 33. 17 - 33.5 - 17.33 + 17 . 5

= 17.5 - 33.5

= 5 ( 17 - 33 )

= 5 . ( -16 )

= -80

Answer 4

18x17-18x7

18(17-7)

18x10

180

b)54-(6x9)+17

54-54+17

1+17

18

c)33-(17+5)

33-32

1

Answer 5

a, 18.17 - 3.6.7 = 6.3.17 - 3.6.7 = 6.3.(17 -7) = 18.10 = 180

b, 54 - 6.(17 + 9) = 54 - 6. 26 = 6.9 - 6.26 = 6.(9 - 26) = 6.(-17) = -102

c, 33.(17 - 5) - 17.(33 - 5) = 33.17 - 33.5 - 17.33 - 17.5 = 33.5 - 17.5 = 5.( 33 - 17) = 5. 6 = 30

Answer 6

a, 18.17 - 3.6.7 = 18.17 - 18.7 = 18. ( 17-7 ) = 18.10 = 180

b, 54 - 6. ( 17+9 ) = 9.6 - 6. 26 = 6. ( 9-26 ) = 6. (-17) = -102

c, 33. ( 17-5 ) - 17. ( 33-5 ) = 33.17 - 33.5 - 17.33 + 17.5

= ( 33.17 - 17.33 ) + ( -33.5 + 17.5 )

= 0 + 5. ( -33+17 )

= 0 + 5. (-16)

= 0 + (-80)

= -80

Answer 7

a) 18.17 - 3.6.7

= 18.17 - 18.7

18.(17 - 7) = 18.10 = 180

b)54 - 6.(17 + 9)

= 9.6 - 6.26 = 6.(9 - 26)

= 6.(-17) = -102

c)33.(17 - 5) - 17.(33 - 5)

= 33.17 - 33.5 - 17.33 + 17.5

= (33.17 - 17.33) + (-33.5 + 17.5)

= 0 + 5.(-33 + 17)

= 5.(-16) = -80

=