17. (x + y)3 + (x + y)2≈ - (x + 1)2 - 28.

20. (a–c)2 - 2 (a − c) (b − d) + (b − d)3.

1. (x + 3a) (x - 3 a), (4y2+ 5 x2) (4 y2 - 5 x2), 6 (2a+3b) (2a-36), (2x-3y) (4x2 + 6 xу + 9 y2).

2. x (xy) (x2 + xy + y2),

1

(a - b) (a + b) (a2 + b2) (a1 + b*),
xy (x + y) (x2- xy + y2),

2 xyz (x+2x) (x - 2x).

3. (a2b)
2 b3) (a2 + 2 b2), (x2

xy

+ xy + y2) (x2 − xy + y2),

(a + b)3 (a - b)3 (a + b + c) (a + b −c).

4. (a + b + c + d) (a + b

(a + b (a + b

- с

d),

b + c + d),

c + d) (a
b + c).
c) (a

5. 5 (2x+9), 3 (2 x + 7), (3 a + b − c) (a + b −c).

6. (x2 + xy + y2) { (x
(x2 + xy + y2) (2

xy + y2) (x + y)2 (x − y)2.

7. (x 10) (x + 7), (x + 1) (x + 10),
(a76) (a8b), (x - 16) (x + 12).

8. (ax +7 by) (ax – 6 by), 3 a (x - 10) (x + 2), ac (c-8) (c + 3).

9. (3x+5) (2 x 7), (2 x + 9) (4 x 15), 3 (2x+3) (3x- 8), (4 2 – 7) (5 x + 6). 10. xy (3x + y) (x + 3 y), x (5 x + 3 a) (mx + p) (nx + q).

11. x3 + 2x2 + 4x + 8, 3 x1

24 + 3x2 + 9.

(4 x + 5 b),

623 + 12x2 24 x + 48,

12. (a + b)2 - (a + b) (c + d) + (c + d)2, a − b + c + d. 13. a2 + pa3 + qa2 + ra + s, 2 a2.

2. a2 + 12 ab + 54a2b2 + 108 ab3 + 81 b1, 16a2 + 32 a3b + 24 a2b3 + 8 ab3 + b4,

a5 5 a+b+ 10 a3b3 10 a2b3 + 5 ab1 — b3,
108 ab + 144 ab3 64 63.

27 a3

5.

9 a2 + b2 +

3 ab2 63.

3 x2 + 2 x
16 c2 + ď2

+ 2 bd 8 cd,

a2 + 4 b2 + c2 + 4 ab

+ 1,

6 ab + 24 ac

9 (a2 + b2 + c2 + 2 ab + 2 ac + 2 bc).

1+3x-5x+3x-x6, (ax+by)3 + 3 (ax+by) cz + &c.

6. 1 + 7 x + 21 x2 + 35 x3 + 35 x2 + 21 x + 7 x2 + x2, (1 + x)3 + 4 (1 + x)3x2 + 6 (1 + x)2x1 + 4 (1 + x)x® + 208, (a + bx) + 4 (a + bx)3 cx2 + &c.

7. a2x2- 8 a7bxy + 28 ab2x2 - 56 ab3xy3 + 70 a*b*x*y* - 56 a313 3 28 a2b2x2y - 8 ab2x2 + b3y3, + ·

729 x 243x4y2 + 27 x2y - y3,

12 6 a1ob2 + 15 a3b1 — 20 ab® + 15 a1b8 – 6 a2b1o +612.

9. a3 + 3a2b + 3 ab2 + b3. 10. (a - c)3.

12. (x + 1)(x + 2) (x + 3) (x-5) (x6) (x + 5). 13. a (a - b)3 (a2 — ab + b2).

14. (x1)(x + 1)(x2 + 1) (6 x2 + 5 x2 + 2 x − 1). 15. (a2 - b3).

16. 2x(x2-1) (3 x2 + 3 x − 1) (2 x2 + 2 x − 5) (2 x2 - 2x+5). 17. 3 (x-2)2 (x + 4) (5 x3 + 10 x2 + 20x + 18).