Роздiл 3. Одночлени i многочлени » 473 (3-4)

3) 4 – 12х + 9х2 = 0; (2 – 3х)2 = 0; 2 – 3х = 0; 3х = 2; х = 2/3. 4) (1 + х)(2х – 1) = (х – 1)х – 2; 2х – 1 + 2х2 – х = х2 – х – 2; 2х + 2х2 – х – х2 + х – 1 + 2 = 0; х2 + 2х + 1 = 0; (х + 1)2 = 0; х + 1 = 0; х = –1.