数学X^2-3XY-4Y^2=0(Y不等于0),则(X-2Y)/(X-Y)=?
问题描述:
数学X^2-3XY-4Y^2=0(Y不等于0),则(X-2Y)/(X-Y)=?
X^2-3XY-4Y^2=0(Y不等于0),则(X-2Y)/(X-Y)=?
我算出了一个答案2/3
还有一个答案算不出
答
X^2-3XY-4Y^2=(X-4Y)(X+Y)=0
X1=4Y,(X-2Y)/(X-Y)=2Y/3Y=2/3
X2=-Y,(X-2Y)/(X-Y)=-3Y/-2Y=3/2