f.2 factorize

1.t^2-st-t+s
=t^2-t+-st+s
=t(t-1)-s(t-1)
=(t-s)(t-1)

2.q^3+q^2-q-1
=q^3-q+q^2-1
=q(q^2-1)+(q^2-1)
=(q+1)(q^2-1)

3.x^2-a^2-b^2-2ab
=x^2-(a^2+2ab+b^2)
=x^2-(a+b)^2
=(x+a+b)[x-(a+b)]
=(x+a+b)(x-a-b)

4.t^2-g^2+2t-4g-3
=t^2+2t+1-g^2-4g-4
=(t+1)^2-(g+2)^2
=(t+1+g+2)[t+1-(g+2)]
=(t+g+3)(t-g-1)

5.x^3-6x^2+11x-6
=x(x^2-6x+11)-6
=x(x^2-6x+5)-6+6x
=x(x-1)(x-5)-6(x-1)
=(x-1)[x(x-5)-6]
=(x-1)(x^2-5x-6)
=(x-1)(x-2)(x-3)

2008-03-27 08:05:02 補充：
第2題,仲要化簡
2.q^3+q^2-q-1
=q^3-q+q^2-1
=q(q^2-1)+(q^2-1)
=(q+1)(q^2-1)
=(q+1)(q+1)(q-1)
=(q-1)(q+1)^2

1.
t^2-st-t+s
=t(t-s)-(t-s)
=(t-s)(t-1)

2.
q^3+q^2-q-1
=q^2(q+1)-(q+1)
=(q^2-1)(q+1)
=(q-1)(q+1)(q+1)

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

4.
t^2-g^2+2t-4g-3
=t^2-2t+1-g^2-4g-4
=(t+1)^2-(g+2)^2
=(t+1-g-2)(t+1+g+2)
=(t-g-1)(t+g+3)

5.x^3-6x^2+11x-6
=x(x^2+6x+5)+6x-6
=x(x+1)(x+5)+6(x+1)
=(x+1)[x(x+5)+6]
=(x+1)(x^2+5x+6)
=(x+1)(x+2)(x+3)

1. (t - s)(t - 1)
2. (q - 1)(q + 1)(q + 1)
3. (x + a + b)(x - a - b)
4. (t+g)(t-g) +2(t-g) -2g-3
or (t-g)(t+g+2) - 2g-3
第四條唔係好識
5. (x - 1)(x - 2)(x - 3)