Question

Tính hợp lý :

a) 2575 - 57 - 2585 + 47

b) 123 -234 + 177 - 166

Answer 1

a)2575-57-2584+47

=(2575-2585)-(57-47)

=(-10)-10

=-20

b)123-234+177-166

=(123+177)-(234+166)

=300-400

=-100

Answer 2

a)2575-57-2584+47

=(2575-2585)-(57-47)

=-10-10

Answer 3

2575-57-2585+47

=2575+(-57)+(-2585)+47

=(2575+47)+[-57+(-2585)]

=2622+(-2642)

=20

b)123-234+177-166

=123+(-234)+177+(-166)

=(123+177)+[-234+(-166)]

=300+(-400)

=-100

Answer 4

a) =(2575-2585)-57+47

=-10-10=-20

b)(123+177)-234-166=300-400=-100

Answer 5

a) 2575 - 57 - 2585 + 47 

= (2575 - 2585) - ( 57 - 47 )

= -10 - 10

= -20

b) 123 -234 + 177 -166

= ( 123 + 177) - ( 234 + 166)

= 300 - 400 

= -100

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