S.3 Mathematics!!!!(factorization of simple polynomials)

1.
= (a + b)(a - b) - c(a - b)
= ( a+ b - c)(a - b).
2.
= [t + ( t - 1)][ t^2 + t(t-1) + (t -1)^2]
= (2t -1)(t^2 + t^2 - t + t^2 + 1 - 2t)
= (2t -1)(3t^2 - 3t + 1).

2008-09-21 21:07:48 補充：
Correction: Q2. should be (2t-1)[t^2 - t(t-1) + (t-1)^2] = (2t-1)(t^2 - t^2 + t + t^2 + 1 - 2t)
= (2t-1)(t^2 -t + 1). Sorry.