2). a? - 16(a-b)？ =[a+4(a-b)][a-4(a-b)]=(5a-4b)(-3a+4b)

3)x？ -2xy+y？ +2x-2y-3

=(x？ -2xy+y？ )+(2x-2y)-3

=(x-y)？ +2(x-y)-3

=(x-y+3)(x-y- 1) (the last step is cross multiplication decomposition).

4)x？ -3xy- 10ya^3-2a^2b-a+2b

=(x-5y)(x+2y) (decomposition by cross multiplication)

5)(x？ +4)? - 16x？

=(x？ +4+4x)(x？ +4-4x) (square difference formula)

=(x+2)？ (x-2)？ (Complete Square Formula)

6)a^3-a+2b-2a^2b

=a^3-2a？ b-a+2b

=(a^3-2a？ B)-(a-2b) (grouping)

=a？ (a-2b)-(a-2b) (extracting common factor)

=(a？ -1)(a-2b) (extracting common factor)

=(a+ 1)(a-b)(a-2b) (square difference formula)

7) 144x^2-(-y)^2

= 144x^2-y^2=( 12x+y)( 12x-y)

8)(x+m)^2-(y+m)^2

=(x+m)+(Y+m)(x+m)-(y+m)

=x+m+Y+mx+m-y-m

=(x+y+2m)(x+y)

9)4(a+b)^2-9(a-b)^2

=2(a+b)+3(a-b)2(a+b)-3(a-b)

=2a+2b+3a-3b2a+2b-3a+3b

=(5a-b)(-a+5b)

10)a^4-8 1b^4

=(a^2+9b^2)(a^2-9b^2)

=(a^2+9b^2)(a+3b)(a-3b)

1 1)4x^3y-9xy^3=xy(4x^2-9y^2)=xy(2x+3y)(2x-3y)

12)x(x- 1)(x-2)-6=x^3-3x^2+2x-6=x^2(x-3)+2(x-3)=(x^2-2)(x-3)

13)ab(x^2+ 1)+x(a^2+b^2)

=abx^2+ab+xa^2+xb^2

=abx^2+xa^2+xb^2+ab

=ax(bx+a)+b(a+bx)

=(ax+b)(bx+a)

Select: 1. Among the following types, the deformation from left to right belongs to the decomposition factor (C).

Answer. a(a+b- 1)=a^2+ab-a·a^2-a-2 = a(a- 1)-2

c。 -4 a^2+9b^2=(-2a+3b)(2a+3b)d . 2x+ 1 = x(2+ 1/x)

2, in the following polynomial, can use the common factor method to decompose the factor is (b).

A.x^2-y·x^2+2x·x^2+y^2 d.x^2-xy+y^2