23. $$(2x - 1)^2 - (2x + 1)^2 = 4$$
Раскроем скобки:
$$4x^2 - 4x + 1 - (4x^2 + 4x + 1) = 4$$
$$4x^2 - 4x + 1 - 4x^2 - 4x - 1 = 4$$
$$-8x = 4$$
$$x = -\frac{4}{8} = -\frac{1}{2}$$
24. $$(3x + 1)^2 - (3x - 1)^2 = 6$$
Раскроем скобки:
$$9x^2 + 6x + 1 - (9x^2 - 6x + 1) = 6$$
$$9x^2 + 6x + 1 - 9x^2 + 6x - 1 = 6$$
$$12x = 6$$
$$x = \frac{6}{12} = \frac{1}{2}$$
Ответ: 23. $$x = -\frac{1}{2}$$; 24. $$x = \frac{1}{2}$$