一式两边乘以-1,得x²+3x+2<0,加上二式得2x²+4≤0,所以2x²≤-4,所以x²≤-2,x没解。
-x²-3x-2>0x²+3x+2<0(x+1)(x+2)<0-2<x<-1x²-3x+2=0(x-1)(x-2)=0x1=1, x2=2
-x²-3x-2>0x²+3x+2<0所以-2x²-3x+2=0x1=1,x2=2
-x²-3x-2>0x²+3x+2<0(x+1)(x+2)<0-2 x²-3x+2=0(x-1)(x-2)=0x=1或x=2