thấy (100-99)+(98-97)+(96-95)+(94-93)+(92-91)+90
=1+1+1+1+1+90
=95
100 - 99 + 98 - 97 + 96 - 95 + 94 - 93 + 92 - 91 + 90 = 95
100-99+98-97+96-95+94-93+92-91+90
=1+1+1+1+1+90
=95
100-99+98-97+96-95+94-93+92-91+90 (100-990)+(98-97)+(96-95)+(94-94)+(92-91)+90 1 + 1 + 1 + 1 + 1 +90 =95
( 100 - 99 ) + ( 98 - 97 ) + ( 96 - 95 ) + ( 94 - 93 ) + ( 92 - 91 ) + 90
= 1 + 1 + 1 + 1 + 1 + 90
= 5 + 90
= 95
( 100 - 99) + (98 - 97) + (96 - 95) + (94 - 93) + (92 - 91) + 90
= 1 +1 + 1 + 1 + 1 + 90
= 95
