-7n(2次方)+57n+1660=0
回答 (6)
2006-11-17 7:15 am
✔ 最佳答案
-7n^2+57n+1660=07n^2-57n-1660=0
(7n+83)(n-20)=0
n=-83/7 or 20
2006-11-17 7:53 am
-7n^2 + 57n + 1660 = 0
7n^2 - 57n - 1660 = 0
(7n + 83) (n - 20) = 0
7n + 83 = 0 or n - 20 = 0
7n = -83 or n = 20
n = -83/7 or n = 20
7n^2 - 57n - 1660 = 0
(7n + 83) (n - 20) = 0
7n + 83 = 0 or n - 20 = 0
7n = -83 or n = 20
n = -83/7 or n = 20
參考: myself
2006-11-17 7:27 am
n=(-(57)±√(57×57-4(-7)(1660))÷2(-7)
n=(-57±223)÷(-14)
n=(-57+223)÷(-14) or n=(-57-223)÷(-14)
N=-166/14 n=20
n=(-57±223)÷(-14)
n=(-57+223)÷(-14) or n=(-57-223)÷(-14)
N=-166/14 n=20
參考: Me
2006-11-17 7:19 am
Ans: (-7n^2-83)x(n-20)
2006-11-17 7:18 am
-7n^2+57n+1660=0
n= [-(57)± √57^2-4(-7)(1660)]/2(17)
n=(-57± 223)/34
n=-11.85714 or 20
n= [-(57)± √57^2-4(-7)(1660)]/2(17)
n=(-57± 223)/34
n=-11.85714 or 20
2006-11-17 7:15 am
-7n(2次方)+57n+1660=0
7n(2次方)-57n-1660=0
(7n+20)(n-83)=0
n=-20/7 or n-83
2006-11-16 23:16:33 補充：
sorry. typed wrongly.(7n+83)(n-20)=0n=-83/7 or n=20
7n(2次方)-57n-1660=0
(7n+20)(n-83)=0
n=-20/7 or n-83
2006-11-16 23:16:33 補充：
sorry. typed wrongly.(7n+83)(n-20)=0n=-83/7 or n=20
收錄日期: 2021-04-12 20:21:27
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https://hk.answers.yahoo.com/question/index?qid=20061116000051KK04893