Question

x^2+x-12=0 x^2-√2 x-1／4=0 x^2+4x+8=2x+11 x(x-4)=2-8x x^2+2x=0 要过程 急急

x^2+x-12=0
x^2-√2 x-1／4=0
x^2+4x+8=2x+11
x(x-4)=2-8x
x^2+2x=0
要过程
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Answer 1

解
x²+x-12=0
(x-3)(x+4)=0
x-3=0或x+4=0
x1=3, x2=-4

x²-(√2)x-1/4=0
x²-(√2)x=1/4
x²-(√2)x+(√2/2)²=1/4+(√2/2)²
(x-√2/2)²=3/4
x-√2/2=±√(3/4)
x-√2/2=±√3/2
x-√2/2=√3/2或x-√2/2=-√3/2
x1=(√2+√3)/2, x2=(√2-√3)/2

x²+4x+8=2x+11
x²+4x-2x+8-11=0
x²+2x-3=0
(x-1)(x+3)=0
x-1=0或x+3=0
x1=1, x2=-3

x(x-4)=2-8x
x²-4x=2-8x
x²-4x+8x=2
x²+4x=2
x²+4x+4=2+4
(x+2)²=6
x+2=±√6
x+2=√6或x+2=-√6
x1=-2+√6, x2=-2-√6

x²+2x=0
x(x+2)=0
x=0或x+2=0
x1=0, x2=-2

Answer 2

1.(x+4)(x-3)=0 x=3 or x=-4
2.求根公式 x=(-(-√2)+-√((-√2)^2-(-1/4*4)))/2 x=(√2+√3)/2 or x=(√2-√3)/2
3. x^2+2x-3=0 (x+3)(x-1)=0 x=-3 or x=1
4. x^2+4x-2=0 求根公式 x=(-4+-√(16+8))/2=-2+-√6 x= √6-2 or x=-√6-2
5 x(x+2)=0 x=0 or x=-2...
这个做起来比打字容易多了，你好好练练吧

Answer 3

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