Решить уравнения 7(x-1)=3x, 7(-3+2x)=-6x-1

№1

7(x - 1) = 3x;

7х - 7 = 3х;

7х - 3х - 7 = 0;

4х = 0 + 7;

4х = 7;

х = 7 : 4;

х = 7/4 = 1 3/4.

Проверка:

7(1 3/4 - 1) = 3 * 1 3/4;

7(7/4 - 1) = 3 * 7/4;

7(7/4 - 4/4) = 21/4;

7 * 3/4 = 21/4;

21/4 = 21/4.

Ответ: х = 7/4 = 1 3/4.

№2

7(-3 + 2x) = -6x - 1;

-21 + 14х = -6х - 1;

14х + 6х = -1 + 21;

20х = 20;

х = 20 : 20;

х = 1.

Проверка:

7(-3 + 2 * 1) = -6 * 1 - 1;

7(-3 + 2) = -6 - 1;

7 * (-1) = -7;

-7 = -7.

Ответ: х = 1.