Question

tính nhanh 

475+666+334-1000

1245-238+755-572+45

(434+191)-(191-434)

472-186-172+986

Answer 1

475+(666+334)-100-=475+1000-1000=475

1245-238+755-572+45=(1245+755+45)-(238+572)=2045-810=1235

(434+191(-(191-434)=434+191-191+434=868

472-186-172+986=(472-172)+(986-186)=300+800=1100

Answer 2

475 + 666 + 334 - 1000

= 475 + ( 666 + 334  ) -1000 

= 475 + 1000 + 1000

= 1475 - 1000

= 475

1245 - 238 + 755 - 572 + 45

= 1245 - ( 238 + 572 ) + ( 755 + 45 )

= 1245 - 810 - 800

= 1245 - 10

= 1235

( 434 + 191 ) - ( 191 - 434 )

= ( 434 - 434 ) - ( 191- 191 )

= 0 - 0 

= 0

472 - 186 - 172 + 986

= ( 472 - 172 ) + ( 986 - 186 )

= 300 + 800

= 1100