中二Questions--- 急急急急急急急...Plz help me to answer ...THX~

8.
(f)
( x - 3 )* - 4x* = [ ( x - 3 ) + 2x ] [ ( x - 3 ) - 2x ]
= ( 3x - 3 ) ( - x - 3 ) = - 3 ( x - 1 ) ( x + 3 )
-----------------------------------------
9.
(c)
( x* - y )* + 10( x - 2 ) + 25 = ? {條數好似有點問題}

(d)
( 4x* - 9y* ) - 2x - 3y = ( 2x + 3y ) ( 2x - 3y ) - ( 2x + 3y ) = ( 2x + 3y + 1 ) ( 2x - 3y )

(e)
( x* - 6x + 9 ) - 4y = ( x - 3 )* - 4y {條數好似有點問題}
is it ( x* - 6x + 9 ) - 4y*? if yes, the answer should be the following.
( x* - 6x + 9 ) - 4y* = ( x - 3 )* - ( 2y )* = ( x - 3 + 2y ) ( x - 3 - 2y )

(f)
9a* - (b* + 26b + 169 ) = (3a)* - ( b + 13 )* = ( 3a + b + 13 ) ( 3a - b - 13 )

remark : * = 二次方(square)

8F (x-3)* -4x*
= [(x-3)-4x][(x-3)+4x]
=(-3-3x)(5x-3)
=-(3x+3)(5x-3)

9. (d)
(4x* - 9y*)-2x-3y
=(2x+3y)(2X-3y)-(2x+3Y)
=(2X+3Y)(2x-3Y-1)

9 (e)
(x* -6x+9)-4y
=(x-3)(x-3)-4Y
=(X-3)*-4Y (我個人覺得呢題係5係4Y*ar-.-個答案甘怪的)

(f)
9a*-(b* +26b+169)
= 9a*-(b+13)*
=(3a+b+13)(3a-b-13)

8.(f)
(x-3)* -4x*
=x*-6x+9-4x*
=-3x*-6x+9
=-3(x*-2x+3)

9.(c)
(x* - y)*+10(x-2)+25
=x**-2x*y+y*+10x-20+25
=x**-2x*y+10x+y*+5

(d)
(4x* - 9y*)-2x-3y
=
(e)
(x* -6x+9)-4y
=
(f)
9a*-(b* +26b+169)
=

All : (x-y)*=x*-2xy+y*
Do it by yourself !

8.(f) (x-3-2x)(x-3+2x)=-(x+3)(x-3)
9.(c) 應該打錯題目..我估應該係..(x-2)^2+10(x-2)+25=(x-2+5)^2=(x+3)^2
(d) (2x-3y)(2x+3y)-(2x+3y)=(2x+3y)(2x-3y-1)
(e) (x-3)^2-4y^2=(x-3-2y)(x-3+2y)<--- 題目的y應該有2次方
(f) 9a^2-(b+13)^2=(3a-b-13)(3a+b+13)
這只是我的少少愚見...

８.42
9c.x9
9d.44
9e.563
9f.9941