Упростить...

Решите задачу:

$1. 4c(c-2)-(c-4)^2=4c^2-8c-c^2+8c-16=3c^2-16$
$2. 3a(a+2)-(a+3)^2=3a^2+6a-a^2-6a-9=2a^2-9.$
$3. 3(y-1)^2+6y=3y^2-6y+3+6y=3y^2+3.$
$4. 8c+4(1-c)^2=8c+4-8c+c^2=4+c^2$
$5. 4ab+2(a-b)^2=4ab+2a^2-4ab+2b^2=2a^2+2b^2.$
$6. 3(x+y)^2-6xy=3x^2+6xy+3y^2-6xy=3x^2+3y^2.$
$7. 3a(a-2)-(a-3)^2=3a^2-6a-a^2+6a-9=2a^2-9.$
$8. (a-4)^2-2a(3a-4)=a^2-8a+16-6a^2+8a=16-5a^2.$
$9. (x-y)^2-x(x-2y)=x^2-2xy+y^2-x^2+2xy=y^2.$
$10. a(a-2b)-(a+b)^2=a^2-2ab-a^2-2ab-b^2=-b^2-4ab.$
$11. (a-3)(a-7)-2a(3a-5)=a^2-7a-3a+21-6a^2+10a=$ $-5a^2+21.$
$12. (x-2)(x+4)-2x(1+x)=x^2+4x-2x-8-2x-2x^2=-x^2-8$ $.$
$13. 2c(3c+4)-3c(2c+1)=6c^2+8c-6c^2-3c=5c.$
$14. 3a(2a-1)-2a(4+3a)=6a^2-3a-8a-6a^2=-11a.$
$15. (b+c)(b-c)-b(b-2c)=b^2-c^2-b^2+2bc=-c^2+2bc.$
$16. (a-c)(a+c)-c(3a-c)=a^2-c^2-3ac+c^2=a^2-3ac.$
$17. a(a+5b)-(a+b)(a-b)=a^2+5ab-a^2+b^2=b^2+5ab.$
$18. b(3a-b)-(a-b)(a+b)=3ab-b^2-a^2+b^2=-a^2+3ab.$
$19. (y+10)(y-2)-4y(2-3y)=y^2-2y+10y-20-8y+12y^2=$ $13y^2-20.$
$20. (a-4)(a+9)-5a(1-2a)=a^2+9a-4a-36-5a+10a^2=11a^2$ $-36.$
$21. (2b-3)(3b+2)-3b(2b+3)=6b^2+4b-9b-6-6b^2-9b=-14b$ $-6.$
$22. (3a-1)(2a-3)-2a(3a+5)=6a^2-9a-2a+3-6a^2-10a=$ $-21a+3.$
$23. (m+3)^2-(m-2)(m+2)=m^2+6m+9-m^2+4=6m+13.$
$24. (a-1)^2-(a+1)(a-2)=a^2-2a+1-a^2+2a-a+2=-a+3.$
$25. (c+2)(c-3)-(c-1)^2=c^2-3c+2c-6-c^2+2c-1=c-7.$
$26. (y-4)(y+4)-(y-3)^2=y^2-16-y^2+6y-9=6y-25.$
$27. (a-2)(a+4)-(a+1)^2=a^2+4a-2a-8-a^2-2a-1=-9.$
$28. (b-4)(b+2)-(b-1)^2=b^2+2b-4b-8-b^2+2b-1=-9.$