Question

x^3-3x+2=0的解是？(怎么算）

Answer 1

x^3-3x+2=0(X^3-X^2)+(X^2-3X+2)=0X^2(X-1)+(X-1)(X-2)=0(X-1)(X^2+X-2)=0(X-1)(X+2)(X-1)=0(X-1)^2(X+2)=0有：(X-1)^2=0X-1=0X1=1又：X+2=0X2=-2

Answer 2

x^3-1-3x+3=0(x-1)(x^2+x+1)-3(x-1)=0(x-1)(x^2+x-2)=0(x-1)(x-1)(x+2)=0x=1或－２

Answer 3

x=1