1) 16x^2 - 4y^2 + 12y - 9
2) x^2 - y^2 + 4x + 8y - 12
3) (5x - 3) (2x + 1) - 18
easy maths(10m)
2007-12-10 2:25 am
回答 (1)
2007-12-10 3:05 am
✔ 最佳答案
1) 16x^2 - 4y^2 + 12y - 9=16x^2 -( 4y^2 - 12y + 9)
=(4x)^2-(2y-3)^2
=(4x-2y-3)(4x+2y-3)
2) x^2 - y^2 + 4x + 8y - 12
=x^2 + 4x+4-y^2 + 8y -16
=(x+2)^2-(y^2-8y+16)
=(x+2)^2-(y-4)^2
=(x+2-y+4)(x+2+y-4)
3) (5x - 3) (2x + 1) - 18
=10x^2+5x-6x-3-18
=10x^2-x-21
=(5x+7)(2x-3)
參考: MYSELF
收錄日期: 2021-04-29 18:18:45
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20071209000051KK03342