Math in a puzzle

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Across
  1. 1. (4y−5)(16y²+20y+25)
  2. 3. (x+5)²
  3. 6. (x+3)(x²−3x+9)
  4. 9. (x-6)²
  5. 10. (x+5)(x+2)
  6. 12. (7y+6)(7y−6)
  7. 14. (x+4)(x+5)
  8. 15. (3x+4)(3x−4)
  9. 16. (4x+9)(4x−9)
  10. 19. (x-6)(x+2)
Down
  1. 2. (3x+2)(9x²−6x+4)
  2. 4. (x+7)²
  3. 5. (2x+5)(2x−5)
  4. 6. (x+3)(x−3)
  5. 7. (x+3)²
  6. 8. (x+2)(x²-2x+4)
  7. 11. (x+7)(x-3)
  8. 13. (x-2)(x-3)
  9. 17. (x+5)²
  10. 18. (2x-1)(4x²+2x+1)