[(4x^2-1)/(2-4x)]/[(4x^2+4x+1)/x]
=[(2x+1)(2x-1)/2(1-2x)]/[(2x+1)²/x]
=[(2x+1)(2x-1)/2(1-2x)]×[x/(2x+1)²]
=-[(2x+1)(2x-1)/2(2x-1)]×[x/(2x+1)²]
=-x/2(2x+1)
=-(-1/4)/2[2×(-1/4)+1]
=(1/4)/[-1+2]
=1/4
[(4x^2-1)/(2-4x)]/[(4x^2+4x+1)/x]
=[(2x+1)(2x-1)/2(1-2x)]/[(2x+1)²/x]
=[(2x+1)(2x-1)/2(1-2x)]×[x/(2x+1)²]
=-[(2x+1)(2x-1)/2(2x-1)]×[x/(2x+1)²]
=-x/2(2x+1)
=-(-1/4)/2[2×(-1/4)+1]
=(1/4)/[-1+2]
=1/4