Question

tính hợp lí (75-2006+42)-(75-43)

Answer 1

(76-2006+42)-(75-43)

=76-2006+42-75+43

=76-75 +42+43-2006

=1+85-2006

=86-2006

=-1920

Answer 2

(76-2006+42)-(75-43)

=76-2006+42-75+43

= (76-2006)+(42+43-75)

=-1930+10

=-1920

Answer 3

( 76 - 2006 + 42 ) - ( 75 - 43 ) 

= 76 - 75 - 2006 + 42 + 43 

= 1 - 2006 + 85 

= -2005 + 85 

=  1920 . 

Answer 4

= 76-2006+42-75 +43

=(76-75) + (42+43) -2006

= 1+85-2006=86-2006=-1920

Answer 5

(76-2006+42)-(75-43)

=76-2006+42-75+43

=76-75 +42+43-2006

=1+85-2006 =86-2006

=-1920