Вправи: 462

462. Розв’яжіть рівняння:

1) (3 + х)² – х² = 0;

9 + 6x + х² – х² = 0;

9 + 6х = 0;

6x = –9;

х = –32;

x = –1,5;

2) (2x – 1)² – 4x² = 0;

4x² – 4х + 1 – 4x² = 0;

–4х + 1 = 0;

4x = 1;

x = 0,25;

3) x² – (5 – х)² = 0;

x² – 25 + 10x – x² = 0;

10x = 25;

х = 2,5;

4) (4x – 1)² – 4x(4x + 1) = 1;

16x² – 8x +1 – 16x² – 4x = 1;

–12x + 1 = 1;

–12x = 0;

х = 0;

5) (5 + x)² – х(х + 5) = 0;

25 + 10x + x² – x² – 5x = 0;

25 + 5x = 0;

5x = –25;

x = –5.