当x>2/3时（2x-1)(3x-2)>=5 6x^2-7x-3>=0 (3x+1)(2x-3)>=0 x>=3/2另外一个舍去当1/2（2x-1)(2-3x)>=5 -6x^2+7x-7>=0 6x^2-7x+7<=0b^2-4ac<0，所以无解当x<1/2时（1-2x)(2-3x)>=56x^2-7x-3>=0(3x+1)(2x-3)>=0x<=-1/3另外一个舍去所以x<=-1/3或 x>=3/2
