數學唔識點算>M< f.2(*20點)

1.)
ps - 2p - 6s + 12
= (ps - 2p) - (6s - 12)
= p(s - 2) - 6(s - 2)
= (p - 6)(s - 2)


2.)
cr + cs - dr - ds
= (cr + cs) - (dr + ds)
= c(r + s) - d(r + s)
= (c - d)(r + s)


3)
tu - tv + 6v - 6u
= tu - tv - 6u + 6v
= (tu - tv) - (6u - 6v)
= t(u - v) - 6(u - v)
= (t - 6)(u - v)


4)
(3x - 2)(a - b) + 3(a - b)
= [(3x - 2) + 3](a - b)
= (3x - 2 + 3)(a - b)
= (3x + 1)(a - b)


5)
(a + 2b)(x - 1) - (1 - x)(2a - c)
= (a + 2b)(x - 1) + [-(1 - x)](2a - c)
= (a + 2b)(x - 1) + (x - 1)(2a - c)
= [(a + 2b) + (2a - c)](x - 1)
= (a + 2b + 2a - c)(x - 1)
= (3a + 2b - c)(x - 1)


6)
(x - 5)² + 2x - 10
= (x - 5)² + 2(x - 5)
= [(x - 5) + 2](x - 5)
= (x - 5 + 2)(x - 5)
= (x - 3)(x - 5)

1.)ps- 2p- 6s + 12
=p(s-2)-6(s-2)
=(p-6)(s-2)

2.)cr + cs -dr -ds
=c(r+s)-d(r+s)
=(c-d)(r+s)

3) tu - tv +6v - 6u
=t(u-v)+6(v-u)
=t(u-v)-6(u-v)
=(t-6)(u-v)

4) (3x-2)(a-b)+3(a-b)
=(3x-2+3)(a-b)
=(3x-1)(a-b)

5)(a+2b)(x-1)-(1-x)(2a-c)
=(a+2b)(x-1)-(2a-c)(1-x)
=(a+2b)(x-1)-(2a-c)(-x+1)
=(a+2b)(x-1)+(2a-c)(x-1)
=(a+2b+2a-c)(x-1)
=(3a+2b-c)(x-1)

6)Factorize(x-5)2次方+2x-10
(x-5)^2+2x-10
=(x-5)^2+2(x-5)