f_ront123
幼苗
共回答了16个问题采纳率：100% 举报
X²+Y²-XY+2X-Y+1=0
(X+1)²+Y²-(X+1)Y=0
(X+1)²+Y²-(X+1)Y+(X+1)²/4-(X+1)²/4=0
(X+1)²+[Y-(X+1)/2]²-(X+1)²/4=0
3(X+1)²/4+[Y-(X+1)/2]²=0
3(X+1)²+4[Y-(X+1)/2]²=0,
3(X+1)²>=0,4[Y-(X+1)/2]²>=0,
X+1=0,X=-1;
Y-(X+1)/2=0,Y-(-1+1)/2=0,Y=0
就是麻烦点,慢慢整理,往恒等式方向使劲,
1年前
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