霹雳火炮
幼苗
共回答了15个问题采纳率:93.3% 举报
解方程:
1. a²x²+b²x-a²-b²=0
a^2(x^2-1)+b^2(x-1)=0
(x-1)[a^2(x+1)+b^2]=0
a^2(x+1)+b^2=0 x-1=0
x1=-b^2/a^2-1 x2=1
2. 3(3x-1)²-5(3x-1)=12
(3x-1)^2-5/3*(3x-1)+25/36=12+25/36=457/36
(3x-1-25/36)^2=457/36
3x-61/36=±√457/6
x1=61/36+√457/6 x2=61/36-√457/6
1年前
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霹雳火炮
3. 2x²-3m-nx+m²-n²=0 x^2-3m-nx/2=(n^2-m^2)/2 [x-(3m-n)/4]^2=(n^2-m^2)/2-(3m-n)^2/16 =[7n^2-17m^2+6mn]/16 x-(3m-n)/4=[7n^2-17m^2+6mn]/4 x=[3m-n(7n^2-17m^2+6mn)]/4