Решите уравнения: (2/3x-4/5) * 15=8

(5/7-2/3y) * 21=1

2/3x+7/3x=18

7/12m+2/3m-1/4m=7

(2/3 х - 4/5) * 15 = 8

2/3 х - 4/5=8/15

2/3 х=8/15 + 4/5

2/3 х=8/15+12/15

2/3 х = 20/15 или 4/3

х=4/3*3/2

х=2

(5/7-2/3 у) * 21=1

5/7 - 2/3 у = 1/21

-2/3 у = 1/21-5/7

-2/3 у = 1/21-15/21

-2/3 у = - 14 / 21 или - 2/3

у = - 2/3 : (-2/3)

у = 1

2/3 х + 7/3 х = 18

9/3 х = 18

х = 18 : 9/3 = 18*1/3

х = 6

7 / 12 m + 2/3 m - 1/4 m = 7

7 / 12m + 8/12m-3/12m=7

12/12m=7

m=7:1

m=7