Помогите с контрольной по алгебре

.01

(12ab – 5a) – (ab + 6a) = 12ab – 5a – ab – 6a = 11ab – 11a;
(x – 8) × (x + 5) = x × (x + 5) – 8(x + 5) = x² – 3x – 40;
(3b – 2) × (4b – 2) = 3b × (4b – 2) – 2(4b – 2) = 12b² – 14b + 4;
5x × (3x² – 2x – 4) = 5x × 3x² – 5x × 2x – 5x × 4 = 15x³ – 10x² – 20x;
(6a + x) × (2a – 3x) = 6a × (2a – 3x) + x × (2a – 3x) = 12a² – 16ax – 3x²;
(c + 1) × (c² + 3c + 2) = c × (c² + 3c + 2) + 1(c² + 3c + 2) = c³ + 4c² + 5c + 2.

.02

3x² + 9xy = 3x × (x + 3y);
2x × (x – 1) – 3(x – 1) = (x – 1) × (2x – 3);
ab + ac + 4b + 4c = a × (b + c) + 4(b + c) = (b + c) × (a + 4).

.03
4x × (a + x + y) + 4a × (a – x – y) – 4y × (x – a – y) = 4ax + 4x² + 4xy + 4a² – 4ax – 4ay – 4xy + 4ay + 4y² = 4x² + 4a² + 4y².

.04

a² + ab – 3a – 3b = a × (a + b) – 3(a + b) = (a + b) × (a – 3);
kp – kc – px + cx + c – p = p × (k – x – 1) – c × (k – x – 1) = (k – x – 1) × (p – c).

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