Решите уравнения(1/3х+1/6х)•2/21=1/3(7/15х-1/3х):1/5+1/3=4

№1

(1/3х + 1/6х) * 2/21 = 1/3;

(2/6х + 1/6х) * 2/21 = 1/3;

3/6х * 2/21 = 1/3;

3/6х = 1/3 : 2/21;

3/6х = 1/3 * 21/2;

3/6х = 7/2;

х = 7/2 : 1/2;

х = 7/2 * 2/1;

х = 7.

Ответ: х = 7.

№2

(7/15х - 1/3х) : 1/5 + 1/3 = 4;

(7/15х - 5/15х) : 1/5 + 1/3 = 4;

2/15х : 1/5 + 1/3 = 4;

2/15х : 1/5 = 4 - 1/3;

2/15х : 1/5 = 12/3 - 1/3;

2/15х : 1/5 = 11/3;

2/15х = 11/3 * 1/5;

2/15х = 11/15;

х = 11/15 : 2/15;

х = 11/15 * 15/2;

х = 11/2 = 5 1/2.

Ответ: х = 11/2 = 5 1/2.