x方 减 x减x方减x分之12等于4

问题描述:

x方 减 x减x方减x分之12等于4

x²-x-12/(x²-x)=4(x²-x)²-12=4(x²-x)(x²-x)²-4(x²-x)-12=0(x²-x-6)(x²-x+2)=0x²-x-6=0或x²-x+2=0x²-x+2=(x-1/2)²+7/4>0,所以x²-x-6=0(...