Question

Bỏ ngoặc rồi tính:

(35+75)+(345-35-75)

(2002-79+15)-(-79+15)

-(515-80+91)-(2003+80-91)

Answer 1

( 35 + 75 ) + ( 345 - 35 - 75 )
= 35 + 75 + 345  - 35 - 75
= ( 35 - 35 ) + ( 75 - 75 ) + 345
= 0 + 0 + 345 
= 345 
( 2002 - 79 + 15 ) - ( -79 + 15 )
= 2002 - 79 + 15 + 79 - 15
= 2002 + ( -79 + 79 ) + ( 15 - 15 )
= 2002 + 0 + 0 
= 2002
- ( 515 - 80 + 91 ) - ( 2003 + 80 - 91 )
= -515 + 80 - 91 - 2003 - 80 + 91
= -515 + ( 80 -80 ) + ( -91 + 91 ) - 2003
= -515 + 0 + 0 - 2003
= - 2518

Answer 2

( 35 + 75 ) + ( 345 - 75 - 35 )

= 35 + 75 + 345 - 75 - 35

= ( 35 + 75 ) - ( 75 + 35 ) + 345

= 110 - 110 + 345

= 0 + 345

= 345

Answer 3

a) (35 + 75) +  (345 - 35 - 75)

= 35 + 75 + 345 - 35 - 75

= (35 - 35) + (75 - 75) + 345

= 0 + 0 + 345

= 345

b) (2002 - 79 + 15) - [ (-79) +15]

= 2002 - 79 + 15 - 79 - 15

= 2002 - (79 - 79) + (15 - 15)

= 2002 - 0 + 0

= 2002

c) -(515 - 80 + 91) - (2003 + 80 - 91)

= -515 + 80 - 91 - 2003 - 80 + 91

= -515 + (80 - 80) + (91 - 91) - 2003

= -515 + 0 + 0 - 2003

= -515 - 2003

= -2518