Вправи: 122

122. Знайдіть корінь рівняння:

1) (4х – 2) + (5х – 4) = 9 – (5 – 11x);

4х – 2 + 5х – 4 = 9 – 5 + 11х;

9х – 11х = 4 + 4 + 2;

–2х = 10;

х = 10 : (–2);

х = –5.

2) (7 – 8х) – (9 – 12х) + (5х + 4) = –16;

7 – 8х – 9 + 12х + 5х + 4 = –16;

9х = –16 – 2;

9х = –18;

х = –18 : 9;

х = –2.

3) 3(4х – 5) – 10(2х – 1) = 33;

12х – 15 – 20х + 10 = 33;

–8х = 33 + 5;

–8х = 38;

х = –4,75.

4) 9(3(х + 1) – 2х) = 7(х + 1);

9(3х + 3 – 2х) = 7х + 7;

9х + 27 – 7х = 7;

2х = 7 – 27;

2х = –20;

х = –10.