mx平方-x-1=0(m>0)x^2-x/m=1/m[x-1/(2m)]^2=(4m+1)/(4m^2)x-1/(2m)=±√(4m+1)/(2m)x=[1±√(4m+1)]/(2m)
mx^2-x-1=0,——》m(x^2-x/m+1/4m^2)-1-m/4m^2=0,——》m(x-1/2m)^2=(4m+1)/4m,——》(x-1/2m)^2=(4m+1)/4m^2,——》x=[1+-v(4m+1)]/2m。
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