Răspuns:
x-1/2 × [x+3/x+1 - x+1/x+4 × (2x+3/x-1 - 1)]
=x-1/2×(x+3/x+1 - x+1/x+4 × 2x+3-(x-1)/x-1)
=x-1/2×(x+3/x+1 - x+1/x+4 × 2x+3-x+1/x-1)
=x-1/2×(x+3/x+1 - (x+1)×1/x-1)
=x-1/2×(x+3/x+1-x+1/x-1)
=x-1/2×(x-1)(x+3)-(x+1)²/(x+1)(x-1)
=1/2 × x²+3x-x-3-(x+1)²/x+1
=1/2×x²+2x-3-(x+1)²/x+1
=x²+2x-3-(x+1)²/2(x+1)
=x²+2x-3-(x²+2x+1)/2x+1
=x²+2x-3-x²-2x-1/2(x+1)
= -4/(2x+1)
=-2/x+1
