解三次方程:x三次方+x平方-5x+3=0,求x?

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解三次方程:x三次方+x平方-5x+3=0,求x?
解三次方程:x三次方+x平方-5x+3=0,求x?

解三次方程:x三次方+x平方-5x+3=0,求x?
x三次方+x平方-5x+3=0
x^3+x^2-2x-(3x-3)=0
x(x^2+x-2)-3(x-1)=0
x(x+2)(x-1)-3(x-1)=0
(x-1)(x^2+2x-3)=0
(x-1)(x+3)(x-1)=0
所以,方程的根为:x1=x2=1,x3=-3

X=1

(x^3)+x^2-5x+3=0
(x^3)+2x^2-3x-x^2-2x+3=0
x(x^2+2x-3)-(x^2+2x-3)=0
(x^2+2x-3)(x-1)=0
(x+3)(x-1)(x-1)=0
∴x[1]=-3,x[2]=x[3]=1

x^3+x^2-5x+3=(x^3-x)+(x^2-4x+3)
=x(x+1)(x-1)+(x-1)(x-3)
=(x-1)(x^2+x+x-3)
=(X-1)(x^2+2x-3)
=(x-1)(x-1)(x+3)=0
x=1,-3