Ответ:

  1. \((y+4)^2=y^2+8y+16\).
  2. \((9+a)^2=a^2+18a+81\).
  3. \((a+c)^2=a^2+2ac+c^2\).
  4. \((x-7)^2=x^2-14x+49\).
  5. \((8-b)^2=b^2-16b+64\).
  6. \((11-y)^2=y^2-22y+121\).
  7. \((5a+1)^2=25a^2+10a+1\).
  8. \((3y-4)^2=9y^2-24y+16\).
  9. \((10+4c)^2=16c^2+80c+100\).
  10. \((2x-3y)^2=4x^2-12xy+9y^2\).
  11. \((5a+6b)^2=25a^2+60ab+36b^2\).
  12. \((-3c+a)^2=a^2-6ac+9c^2\).
  13. \((a^2-3)^2=a^4-6a^2+9\).
  14. \((a-y^2)^2=a^2-2ay^2+y^4\).
  15. \((a^2+b^2)^2=a^4+2a^2b^2+b^4\).