Sắt đoàn
5
1
1) ( 2/3 + 2/5 - 2/7 - 2/11 ) / ( 2 + 6/5 - 6/7 - 6/11 )
2) -4/7 : -1/3
3) 3/5 : (-5)
4) 24 : -6/7
(2/3 - 1 và 1/2):4/3+1/2
-5/13+2/5+-8/13+3/5-3/7
2/7+5/7.(3/5 - 0,25).(-2)^2 +35%
