Умножение многлечленов (5x+6)(2x-9)+4 (6x-7)(5x+2)-9 (9x+8)(2x-9)+4 (5x+6)(2x-9)+9 (6x-7)(5x-2)+8 (2x+8)(2x+9)+5 (2x+8)(3x+9)-5 (x^{2}-5x+9)(5x^{2}+6x+2) (x^{2}-5x+9)(x^{2}-6x+2) (2a^{2}+6a+1)(2a-8a^{2}-3) (2a^{2}+6a+1)(a-5a^{2}-6) (2y+6x)(8a-6y)+7 (2y+6x)(3a-8y)-7 (2k+6y)(5k-8y)+12k (2k+6y)(8k-5y)-12k (-7x+4y)(2x-3y)+13 (-7x+4y)(9x-2y)-13 (8a-3)(6x-1)-6x (8a-3)(-6x-5)+6x (-9a-3)(5x-1)-8x+9a

Here are the solutions to the multiplication of the given polynomial expressions:

1. (5x+6)(2x-9)+4 = 10x^2 - 3x - 54 + 4 = 10x^2 - 3x - 50

2. (6x-7)(5x+2)-9 = 30x^2 + 17x - 14x - 14 - 9 = 30x^2 + 3x - 23

3. (9x+8)(2x-9)+4 = 18x^2 - 81x + 16x - 72 + 4 = 18x^2 - 65x - 68

4. (5x+6)(2x-9)+9 = 10x^2 - 45x + 12x - 54 + 9 = 10x^2 - 33x - 45

5. (6x-7)(5x-2)+8 = 30x^2 - 12x - 35x + 14 + 8 = 30x^2 - 47x + 22

6. (2x+8)(2x+9)+5 = 4x^2 + 18x + 16x + 72 + 5 = 4x^2 + 34x + 77

7. (2x+8)(3x+9)-5 = 6x^2 + 18x + 24x + 72 - 5 = 6x^2 + 42x + 67

8. (x^2 - 5x + 9)(5x^2 + 6x + 2) = 5x^4 + 6x^3 + 2x^2 - 25x^3 - 30x^2 - 10x + 45x^2 + 54x + 18 = 5x^4 - 19x^3 + 17x^2 + 44x + 18

9. (x^2 - 5x + 9)(x^2 - 6x + 2) = x^4 - 6x^3 + 2x^2 - 5x^3 + 30x^2 - 10x + 9x^2 - 54x + 18 = x^4 - 11x^3 + 41x^2 - 64x + 18

10. (2a^2 + 6a + 1)(2a - 8a^2 - 3) = 4a^3 - 16a^4 - 6a^2 + 12a - 48a^3 - 18a - 8a^2 + 32a^3 + 12a - 6 = -16a^4 - 12a^3 - 6a^2 + 12a - 18a

11. (2a^2 + 6a + 1)(a - 5a^2 - 6) = 2a^3 - 10a^4 - 12a^2 + 6a + 6a - 30a^3 - 36a - 3a^2 + 15a^3 + 18a + 3 = -10a^4 - 7a^3 - 15a^2 + 30a + 3

12. (2y + 6x)(8a - 6y) + 7 = 16ay - 12y^2 + 48ax - 36xy + 7

13. (2y + 6x)(3a - 8y) - 7 = 6ay - 16y^2 + 18ax - 48xy - 7

14. (2k + 6y)(5k - 8y) + 12k = 10k^2 - 16ky + 30ky - 48y^2 + 12k = 10k^2 + 14ky - 48y^2 + 12k

15. (2k + 6y)(8k - 5y) - 12k = 16k^2 - 10ky + 48ky - 30y^2 - 12k = 16k^2 + 38ky - 30y^2 - 12k

16. (-7x + 4y)(2x - 3y) + 13 = -14x^2 + 21xy + 8xy - 12y^2 + 13 = -14x^2 + 29xy - 12y^2 + 13

17. (-7x + 4y)(9x - 2y) - 13 = -63x^2 + 14xy + 36xy - 8y^2 - 13 = -63x^2 + 50xy - 8y^2 - 13

18. (8a - 3)(6x - 1) - 6x = 48ax - 8a - 18x + 3 - 6x = 48ax - 24x - 6a - 5x + 3

19. (8a - 3)(-6x - 5) + 6x = -48ax - 40x + 18x + 15 + 6x = -48ax - 16x + 21

20. (-9a - 3)(5x - 1) - 8x + 9a = -45ax + 9a - 15x + 3 - 8x + 9a = -45ax + 18a - 23x + 3