一元二次不等式求解 x^2-2x-3>0 x^2-2x-3<0 4x^2+4x-30 ..一元二次不等式求解x^2-2x-3>0x^2-2x-3<04x^2+4x-30

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一元二次不等式求解 x^2-2x-3>0 x^2-2x-3<0 4x^2+4x-30 ..一元二次不等式求解x^2-2x-3>0x^2-2x-3<04x^2+4x-30
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一元二次不等式求解 x^2-2x-3>0 x^2-2x-3<0 4x^2+4x-30 ..一元二次不等式求解x^2-2x-3>0x^2-2x-3<04x^2+4x-30
一元二次不等式求解 x^2-2x-3>0 x^2-2x-3<0 4x^2+4x-30 ..
一元二次不等式求解
x^2-2x-3>0
x^2-2x-3<0
4x^2+4x-30

一元二次不等式求解 x^2-2x-3>0 x^2-2x-3<0 4x^2+4x-30 ..一元二次不等式求解x^2-2x-3>0x^2-2x-3<04x^2+4x-30
x^2-2x-3>0 (x+1)(x-3)>0 所以x>3或x

x^2-2x-3>0,(x-3)(x+1)>0解得x>3或x<-1
x^2-2x-3<0,(x-3)(x+1)<0解得-1<x<3
4x^2+4x-3<0,(2x+3)(2x-1)<0解得-3/2<x<1/2
x^2-4x+5>0,(x-2)^2+1>0恒成立,故x∈R

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x^2-2x-3=(x+1)(x-3) x^2-2x-3>0 => (x+1)(x-3)>0 =>x<-1或x>3
x^2-2x-3<0 => (x+1)(x-3)<0 =>-14x^2+4x-3=(2x-1)(2x+3) 4x^2+4x-3<0 =>-3/2 4x^2+4x-3>0 =>x<-3/2或x>1/2