Роздiл 3. Одночлени i многочлени » 589 (6-7)

6) (2x – 1)2 – 25 = 0; (2x – 1 – 5)(2x – 1 + 5) = 0; (2x – 6)(2x + 4) = 0; 2x – 6 = 0; 2x = 6; x = 3; 2x + 4 = 0; 2x = –4; x = –2. 7) x2 – (3 + х)2 = 0; (x – 3 – x)(x + 3 + x) = 0; –3(x + 3 + x) = 0; –3x – 9 – 3x = 0; –6x = 9; x = –1,5.