F.2 Maths

x^2+22x+121

=(x+11)^2


m^2-6m-55

=(x-11) (x+5)


2x^2-40x+200

=2(x^2-20x+100)

=2(x-10)^2


-9+y^2

=y^2-9

=(y-3) (y+3)


24x^3+375y^3

=3(8x^3+125y^3)

=3(2x+5y) (4x^2-10xy+25y^2)


(2x+3)^2-(x-5)^2

=4x^2+12x+9-(x^2-10x+25)

=4x^2+12x+9-x^2+10x-25

=3x^2+22x-16

=(3x-2)(x+8)

F.2 Maths

x^2 22x 121
=x^2 2(11)(x) 11^2
=(x 11)^2


m -11
m 5
-------------
-11m 5m =-6m

m^2-6m-55
=(m-11)(m 5)

2x^2-40x 200
=2[x^2-20x 100]
=2(x 10)^2

-9 y^2
=-(9-y^2)
=-(3 y)(3-y)

a^3 b^3=(a b)(a^2-ab b^2

24x^3 375y^3
=3[8x^3 125y^3]
=3(2x 5y)(4x^2-10xy 25y^2)

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

(2x 3)^2-(x-5)^2
=[(2x 3) (x-5)][(2x 3)-(x-5)]
=(3x-2)(x 8)

你自己可以試下做

&試下做其他例子

2008-09-28 19:27:33 補充：
a^2-b^2=(a b)(a-b)

(a-b)^2=(a^2-2ab-b^2)

(a+b)^2=(a^2+2ab+b^2)

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

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

可以參考下上面的公式