x的平方-2x-5=0怎么算?
x^2-2x-5=0
x^2-2x+1=6
(x-1)^2=6
x1=√6+1
x2=-√6+1
5x的平方+2x=0怎么算?
5x^2+2x=0
x(5x+2)=0
x=0 或 x= - 2/5
(x+3)的平方=(2x-5)的平方怎么算
(x+3)^2=(2x-5)^2
(x+3)^2-(2x-5)^2=0
(x+3+2x-5)(x+3-2x+5)=0
(3x-2)(-x+8)=0
x=2/3或x=8
x(2x-5)=4x-10怎么算
2x^2-9x+10=0
(x-2)(2x-5)=0
x=2或x=2/5
x^2-2x-5=0
(x-1)^2 = 6
x=1+√6 or 1-√6
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x^2+2x=0
x(x+2)=0
x=0 or -2
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(x+3)^2=(2x-5)^2
[(2x-5) +(x+3) ].[(2x-5) -(x+3) ] =0
(3x-2)(x-8)=0
x=2/3 or 8
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x(2x-5)=4x-10
2x^2-5x=4x-10
2x^2-9x+10 =0
(2x-5)(x-2) =0
x=2 or 5/2