Номер 1.30

Розкладіть на множники тричлен:

1) x2 – x – 4x + 4 = x(x – 1) – 4(x – 1) = (x – 1)(x – 4);

2) y2 + 2y + 3y + 6 = y(y + 2) + 3(y + 2) – (y + 2)(y + 3);

3) a2a – 2 = a2 + a – 2a – 2 = a(a + 1) – 2(a +1) = (a + 1)(a –2);

4) b2 + 3b + 4b + 12 = b(b + 3) + 4(b + 3) = (b + 3)(b + 4);

5) 2x2x – 1 = x2x + x2 – 1 = x(x – 1) +(x – 1)(x +1) = (x – 1)(x + x + 1) = (x – 1)(2x + 1);

6) 3x2 + 4x + 1 = (3x + 1)(x + 1).