2x^2+3x-12>0 怎么算?

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2x^2+3x-12>0 怎么算?

2x^2+3x-12>0 怎么算?
2x^2+3x-12>0 怎么算?

2x^2+3x-12>0 怎么算?
郭敦顒回答:
2x²+3x-12>0
解上不等式,[x1+3/4-(5/4)√42] [x2+3/4+(5/4)√42] >0,
∴(x1-7.3509)(x2+8.8509)>0,
∴当(x1-7.3509)>0,(x2+8.8509)>0时,
x1>7.3509,x2>-8.8509;
∴当(x1-7.3509)<0,(x2+8.8509)<0时,
x1<7.3509,x2<-8.8509.