2.(a+3)2-6(a+3)=(a+3)(a-3)

3(x+ 1)2(x+2)-(x+ 1)(x+2)2 =-(x+ 1)(x+2)

4.abc+ab-4a=a(bc+b-4)

5. 16x 2-8 1 =(4x+9)(4x-9)

6.9x2-30x+25=(3x-5)^2

7.x2-7x-30=(x- 10)(x+3)

8.x2-25=(x+5)(x-5)

9.x2-20x+ 100=(x- 10)^2

10 . x2+4x+3 =(x+ 1)(x+3)

1 1.4x 2- 12x+5 =(2x- 1)(2x-5)

12.3ax2-6ax=3ax(x-2)

13.x(x+2)-x=x(x+ 1)

14.x2-4x-ax+4a=(x-4)(x-a)

15.25x2-49=(5x-9)(5x+9)

16.36x2-60x+25=(6x-5)^2

17.4x2+ 12x+9=(2x+3)^2

18 . x2-9x+ 18 =(x-3)(x-6)

19.2 x2-5x-3 =(x-3)(2x+ 1)

20. 12 x2-50x+8 = 2(6x- 1)(x-4)

2 1.(x+2)(x-3)+(x+2)(x+4)=(x+2)(2x- 1)

22.2 ax2-3x+2ax-3 =(x+ 1)(2ax-3)

23.9x2-66x+ 12 1=(3x- 1 1)^2

24.8-2x2=2(2+x)(2-x)

25.X2-X+ 14 = cannot be decomposed in an integer.

26.9x2-30x+25=(3x-5)^2

27.-20x2+9x+20=(-4x+5)(5x+4)

28. 12 x2-29x+ 15 =(4x-3)(3x-5)

29.36 x2+39x+9 = 3(3x+ 1)(4x+3)

30.2 1x 2-3 1x-22 =(2 1x+ 1 1)(x-2)

3 1.9x4-35x2-4=(9x^2+ 1)(x+2)(x-2)

32.(2x+ 1)(x+ 1)+(2x+ 1)(x-3)= 2(x- 1)(2x+ 1)

33.2 ax2-3x+2ax-3 =(x+ 1)(2ax-3)

34 . x(y+2)-x-y- 1 =(x- 1)(y+ 1)

35.(x2-3x)+(x-3)2=(x-3)(2x-3)

36.9x2-66x+ 12 1=(3x- 1 1)^2

37.8-2x2=2(2-x)(2+x)

38.x4- 1=(x- 1)(x+ 1)(x^2+ 1)

39.x2+4x-xy-2y+4=(x+2)(x-y+2)

40.4 x2- 12x+5 =(2x- 1)(2x-5)

4 1.2 1x 2-3 1x-22 =(2 1x+ 1 1)(x-2)

42.3x2-6x=3x(x-2)

43.49x2-25=(7x+5)(7x-5)

44.6 x2- 13x+5 =(2x- 1)(3x-5)

45.x2+2-3x=(x- 1)(x-2)

46. 12 x2-23x-24 =(3x-8)(4x+3)

47.(x+6)(x-6)-(x-6)=(x-6)(x+5)

48.3(x+2)(x-5)-(x+2)(x-3)= 2(x-6)(x+2)

49.9x2+42x+49=(3x+7)^2。