А) 2 1/14 - 1 2/3x = 1 5/21

б) (8/15 + 2/9y) : 3/5 = 2

г) 2/5m + 3/10m - 2/15m = 1/6

д) z - 8/15z = 1/3

А) 2 1/14 - 1 2/3x = 1 5/21

29/14-5/3x=26/21

-5/3x=26/21-29/14

26/21-29/14=52/42-87/42 = - 35/42

-5/3x = - 35/42

X = 35/42:5/3

X=35/42*3/5

X=7/14=1/2

б) (8/15 + 2/9y) : 3/5 = 2

(8/15 + 2/9y) = 2*3/5

8/15 + 2/9y=6/5

2/9y=6/5-8/15

2/9y=18/15-8/15

2/9y=10/15

2/9y=2/3

Y=2/3:2/9

Y=2/3*9/2

Y=3

г) 2/5m + 3/10m - 2/15m = 1/6

2/5+3/10=4/10+3/10=7/10

7/10-2/15=21/30-4/30=17/30

17/30m=1/6

m=1/6:17/30

m=1/6*30/17

m=5/17

д) z - 8/15z = 1/3

7/15z=1/3

z=1/3:7/15

z=1/3*15/7

z=5/7