6. Решите уравнение. a) (5x-2)(5x+2)-(5x-1)² = 4; б) 100x² - 16 = 0.

Решение: a) (5x - 2)(5x + 2) - (5x - 1)² = 4 (25x² - 4) - (25x² - 10x + 1) = 4 25x² - 4 - 25x² + 10x - 1 = 4 10x - 5 = 4 10x = 9 x = 9/10 = 0.9 б) 100x² - 16 = 0 (10x)² - 4² = 0 (10x - 4)(10x + 4) = 0 10x - 4 = 0 или 10x + 4 = 0 10x = 4 или 10x = -4 x = 4/10 = 0.4 или x = -4/10 = -0.4 Ответ: a) x = 0.9 б) x = 0.4, x = -0.4