【先化简,再求值】【(x²-2x+1)分之x+(1-x)分之1】÷(x²-1)分之2
问题描述:
【先化简,再求值】【(x²-2x+1)分之x+(1-x)分之1】÷(x²-1)分之2
【先化简,再求值】
【(x²-2x+1)分之x+(1-x)分之1】÷(x²-1)分之2
其中x=-2
答
【(x²-2x+1)分之x+(1-x)分之1】÷(x²-1)分之2
=[x/(x-1)²-1/(x-1)×(x+1)(x-1)/2
=(x-x+1)/(x-1)×(x+1)(x-1)/2
=(x+1)/2
当x=-2时
原式=(-2+1)/2=-1/2