a) -11/12x + 3/4 =-1/6
-11/12x=-1/6-3/4
-11/12x=-11/12
x=-11/12:-11/12
x=1
b) 3-(1/6-x).2/3=2/3
(1/6-x).2/3=2/3+3
(1/6-x).2/3=11/3
1/6-x=11/3:2/3
1/6-x=11/2
x=1/6-11/2
x=16/3
c) mik ko bít cách giải thích
11a) tính 1/2.3=1/6
1/2-1/3=1/6
=)1/2.3=1/2-1/3
b)1/1.2+1/2.3+1/3.4+....+1/2005.2006
=(1-1/2)+(1/2-1/3)+(1/3-1/4)+.....+(1/2005-1/2006)
=1-1/2+1/2-1/3+1/3-1/4+....+1/2005-1/2006
=1-1/2006=2005/2006
#Chúc bạn học tốt^^