a) 1/2 - 1/3 + m = 0
3/6-2/6+m=0
1/6+m = 0
m=-1/6
b) 2/5 - 3/4 +m=0
8/20-15/20+m=0
-7/20+m=0
m=7/20=0,35
c) 4/3 - 9/4 - 2m = 0
16/12-27/12-2m = 0
-11/12-2m=0
2m=11/12 /:2
m = 11/24
d) 7/2 - 7/6 + 7/3m=0
21/6-7/6+7/3m = 0
14/6+7/3m=0
7/3m=-14/6 /*3
7m=-7 /:7
m=-1
e) 3/2 - 2/3m - 0,75 = 0
6/4-¾-⅔m=0
¾-⅔m=0
⅔m=¾ /*3
2m=9/4 /:2
m=9/8 = 1⅛