А) 2 1/14 - 1 2/3x = 1 5/21 б)(8/15 + 2/9y) : 3/5 - вопрос №6795752211412315218152935225310215 от genri5673 10.10.2020 08:28

Question

Математика: 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

genri5673 · Answer

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