a) (5+1/3)×6/5
(15/3+1/3)×6/5
16/3×6/5
16/1×2/5
32/5=6,4
b) (6+3/2)×3/10
12+3/2 ×3/10
15/2+3/10
75/10+3/10
78/10=7,8
c) (4-2/5):12/15
(20/5-2/5)×15/12
18/5×15/12
18/5×5/4
18/1×1/4
18/4=4,5
d) (2+5/6)÷17/4
(12/6+5/6)×4/17
17/6×4/17
1/6×4/1= 4/6=0,(6)
