1)1/3*(5/12-4м)=4/9*(1 1/2м-3/8) 2)0,3*(5х-7)=3*(0,2х+3,2) 3)(1,4х-3,5):0,25=(4,6х-18):(-1,5)

1)1/3 * (5/12 4m) = 4/9 * (1 1/2m - 3/8);

5/36 4/3m = 4/9 * (3/2 m 3/8);

5/36 - 4/3m = 12/18 m 1/6;

- 4/3m 12/18m = - 5/36 1/6;

- 4/3m 2/3m = - 5/36 6/36;

- 6/3m = - 11/36;

6/3m = 11/36;

2m = 11/36;

m = 11/36 / 2;

m = 11/72.  

 2)0,3 * (5х - 7) = 3 * (0,2х + 3,2);

1,5х 2,1 = 0,6х + 9,6;

1,5х 0,6х = 9,6 + 2,1;

0,9х = 11,7;

х = 11,7 / 0,9;

х = 13.

3)(1,4х - 3,5) : 0,25 = (4,6х -18 ) : (-1,5);

5,6х 14 = 3 1/15х + 12;

5,6х 3 1/15х = 14 + 12;

56/10х 46/15х = 26;

168/30х 92/30х = 26;

76/30х = 26;

х = 26 / 76/30;

х = 780 / 76;

х = 10 20/76;

х = 10 5/19.