y²＋2y=6
y²＋2y＋1=7
(y＋1)²=7
y＋1=±√7
y=－1±√7[2/(y－3)]＋1=3/[(y－3)(y＋3)]2(y＋3)＋(y－3)(y＋3)=3y²＋2y－6=0(y＋1)²=7y＋1=±√7y=－1±√7