1.x^2-x-202.(x-4)(x+5)=4-x3.x^2+6x-5=04.2x^2-4x-1=0
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1.x^2-x-202.(x-4)(x+5)=4-x3.x^2+6x-5=04.2x^2-4x-1=0
1.x^2-x-20
2.(x-4)(x+5)=4-x
3.x^2+6x-5=0
4.2x^2-4x-1=0
1.x^2-x-202.(x-4)(x+5)=4-x3.x^2+6x-5=04.2x^2-4x-1=0
1.x^2-x-20
=(x-5)(x+4)
2.(x-4)(x+5)=4-x 方程?
(x-4)(x+5-1)=0
(x-4)(x+4)=0
x1=4 x2= -4
3.x^2+6x-5=0
(x+3)²-14=0
x+3=±√14
x1= -3+√14
x2= -3-√14
4.2x^2-4x-1=0
2(x-1)²=3
x-1=±(1/2)√6
x1=1+(1/2)√6
x2=1-(1/2)√6
1.4x5=20, (x-5)(x+4)
2.(x-4)(x+5+1)=(x-4)(x+6)
3.5x1=5, (x+5)(x+1)
4.2(x-2)^2-5=(2x-4+V5)(2x-4-V5)
x^2-x-20
=(x-5)(x+4)
2.(x-4)(x+5)=4-x
(x-4)(x+5)+(x-4)=0
(x-4)(x+6)=0
x=4或x=-6
3|、x^2+6x-5=0
(x+3)²-14=0
(x+3+根号14)(x+3-根号14)=0
x=-(3+根号14)或x=-(3-根号14)
4.2...
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x^2-x-20
=(x-5)(x+4)
2.(x-4)(x+5)=4-x
(x-4)(x+5)+(x-4)=0
(x-4)(x+6)=0
x=4或x=-6
3|、x^2+6x-5=0
(x+3)²-14=0
(x+3+根号14)(x+3-根号14)=0
x=-(3+根号14)或x=-(3-根号14)
4.2x^2-4x-1=0
x²-2x-1/2=0
(x-1)²-5/4=0
(x-1+2分之根号5)(x-1-2分之根号5)=0
x=1-2分之根号5
或x=1+2分之根号5
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