Решение задания смотри на фотографии
(3x - 5)² - (x + 3)² = (3x - 5 - x - 3)(3x - 5 + x + 3) = (2x - 8)(4x - 2)
a^6 - (a + 4)² = (a³ - a - 4)(a³ + a + 4)
(a + b - c)² - (a - b + c)² = (a + b - c - a + b - c)(a + b - c + a - b + c) = 2a(2b - 2c) = 4a(b - c)
2sinx + 2sinx·cosx = 0; /sinx 2 + 2cosx =0; 2cosx = -2; cosx = -1;
x=π +2πn, n∈Z.