因式分解
3) 75(m-3n)^2-27(2m-5n)^2
4) 3u^2-12v^2-6u+12v
mathsssss因式分解thx
2009-08-25 6:13 am
回答 (2)
2009-08-25 6:25 am
✔ 最佳答案
3) 75(m-3n)2-27(2m-5n)2=3[25(m-3n)2-9(2m-5n)2]
=3{[5(m-3n)]2-[3(2m-5n)]2}
=3[5(m-3n)-3(2m-5n)][5(m-3n)+3(2m-5n)]
=3(5m-15n-6m+15n)(5m-15n+6m-15n)
=3(-m)(11m-30n)
=-3m(11m-30n)
4) 3u2-12v2-6u+12v
=3(u2-4v2)-6(u-2v)
=3(u-2v)(u+2v)-6(u-2v)
=3(u-2v)[(u+2v)-2]
=3(u-2v)(u+2v-2)
2009-08-25 6:57 am
因式分解
3) 75(m-3n)^2-27(2m-5n)^2
= 3[25(m-3n)^2-9(2m-5n)^2]
= 3{[5(m-3n)]^2-[3(2m-5n)]^2}
= 3[5(m-3n)-3(2m-5n)][5(m-3n)+3(2m-5n)]
= 3(5m-15n-6m+15n)(5m-15n+6m-15n)
= 3(-m)(11m-30n)
= -3m(11m-30n)
4) 3u2-12v2-6u+12v
= 3(u2-4v2)-6(u-2v)
= 3(u-2v)(u+2v)-6(u-2v)
= 3(u-2v)[(u+2v)-2]
3) 75(m-3n)^2-27(2m-5n)^2
= 3[25(m-3n)^2-9(2m-5n)^2]
= 3{[5(m-3n)]^2-[3(2m-5n)]^2}
= 3[5(m-3n)-3(2m-5n)][5(m-3n)+3(2m-5n)]
= 3(5m-15n-6m+15n)(5m-15n+6m-15n)
= 3(-m)(11m-30n)
= -3m(11m-30n)
4) 3u2-12v2-6u+12v
= 3(u2-4v2)-6(u-2v)
= 3(u-2v)(u+2v)-6(u-2v)
= 3(u-2v)[(u+2v)-2]
參考: By my F.4 Student
收錄日期: 2021-04-23 20:38:12
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20090824000051KK02493