ГДЗ Алгебра 9 клас Істер НУШ

2) (x2 + x)2 – 4x2 – 4x – 12 = 0;
(x2 + x)2 – 4(x2 + x) – 12 = 0;
t = x2 + x; t2 – 4t – 12 = 0;
t1 + t2 = 4; t1 • t2 = –12;
t1 = 6; t2 = –2.
x2 + x = 6; x2 + x – 6 = 0;
x1 + x2 = –1; x1 • x2 = –6;
x1 = –3; x2 = 2. x2 + x = –2;
x2 + x + 2 = 0;
D = 12 – 4 • 1 • 2 = 1 – 8 = –7 < 0.
Відповідь: –3; 2.