Решить уравнение | 8x – 3 | = 21
|8x-3| = 21, 8x-3 = 21 или 8x-3 = -21; 1) 8x-3 = 21; 8x = 21+3 = 24; x = 24/8 = 3. 2) 8x-3 = -21; 8x = -21+3 = -18; x = -18/8 = -9/4 = -(9*25)/100 = = -(180+45)/100 = -225/100 = -2,25. Ответ. {-2,25; 3}