4X²-1/2-4x÷4X²+4X+1/X 先化简,再求值,X=-1/4
问题描述:
4X²-1/2-4x÷4X²+4X+1/X 先化简,再求值,X=-1/4
答
4X²-1/2-4x÷4X²+4X+1/X
=(2x+1)(2x-1)/[-2(2x-1)]× x/(2x+1)²
=-x/[2(2x+1)]
=1/4÷ (-1+2)
=1/4