= mean identity , ^ mean 二次方 , *mean 三次方
If Ax(x-1)(x+2)+Bx(x-1)+Cx+D = 5x* + 3X^ - 10x + 6 , find the values of A,B,C,D.
F.2 MATHS 一題 (快...)
2007-01-07 5:56 pm
回答 (2)
2007-01-07 6:05 pm
✔ 最佳答案
Ax(x-1)(x+2)+Bx(x-1) +Cx+D = 5x* + 3X^ - 10x + 6sub x=0
D=6
sub x=1
C+D=4
C=-2
A=5
5x(x-1)(x+2)+Bx(x-1)
=5x(x^2+x-2)+B(x^2-x)
=5x^3+5x^2-10x+Bx^2-Bx
so compare the x^2 coefficient
5+B=3
B=-2
A=5, B=-2, C=-2, D=6
2007-01-07 10:06:49 補充：
因為x^3得Ax^3一項可以推到A=5
2007-01-08 1:21 am
A=5
B=-2
C=-10
D=6
B=-2
C=-10
D=6
收錄日期: 2021-04-25 16:52:56
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https://hk.answers.yahoo.com/question/index?qid=20070107000051KK00930