Вправи: 867

867. Розв’яжи рівняння.

a) 3(x + 4) + 6(11 – x) = 9;

3x + 12 + 66 – 6x) = 9;

3x – 6x = 9 – 12 – 66;

–3x = –69|: (–3);

x = 23.

б) 8(1 – x) + 5(x – 2) = 2;

8 – 8x + 5x – 10 = 2;

–3x = 2 – 8 + 10;

–3x = 4|: (–3);

x = –43;

x = –113.

в) 7(x – 5) – 3(2x – 6) = 10;

7x – 35 – 6x + 18 = 10;

x = 10 + 35 – 18;

x = 27.

г) 18 + 3(x – 5) + 8x = 2(5 + 2x);

18 + 3x – 15 + 8x = 10 + 4x;

11x – 4x = 10 – 18 + 15;

7x = 7|: 7;

x = 1.