①3x^2-11x-4=0(因式分解法) ②(x+2)(2x-1)=2(配方法) ③x^2+1/x+2x/x^2+1=3

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①3x^2-11x-4=0(因式分解法)②(x+2)(2x-1)=2(配方法)③x^2+1/x+2x/x^2+1=3①3x^2-11x-4=0(因式分解法)②(x+2)(2x-1)=2(配方法)③x^

①3x^2-11x-4=0(因式分解法) ②(x+2)(2x-1)=2(配方法) ③x^2+1/x+2x/x^2+1=3
①3x^2-11x-4=0(因式分解法) ②(x+2)(2x-1)=2(配方法) ③x^2+1/x+2x/x^2+1=3

①3x^2-11x-4=0(因式分解法) ②(x+2)(2x-1)=2(配方法) ③x^2+1/x+2x/x^2+1=3
3x^2-11x-4=0
(3x+1)(x-4)=0
3x+1=0 x=-1/3
x-4=0 x=4
(x+2)(2x-1)=2
2x^2+3x-2=2
2(x^2+3x/2)=4
(x^2+3x/2)=2
(x+3/4)^2=2+(3/4)^2
(x+3/4)^2=41/16
x+3/4=±√41/16
x=-3/4±√41/4
x=(-3+√41)/4
x=(-3-√41)/4
(x^2+1)/x+2x/(x^2+1)=3
[(x^2+1)^2+2x^2]/[x(x^2+1)]=3
(x^2+1)^2+2x^2=3x(x^2+1)
x^4-3x^3+4x^2-3x+1=0
(x-1)x^3-2x^2(x-1)+2x(x-1)-(x-1)=0
(x-1)(x^3-2x^2+2x-1)=0
(x-1)[x^2(x-1)-x(x-1)+(x-1)]=0
(x-1)^2(x^2-x+1)=0
x-1=0 x=1
x^2-x+1=0 w无实根