请问,x=(a+1)/(a-1),y=(2a-3)/(3a-2)用x表示y
问题描述：
请问,x=(a+1)/(a-1),y=(2a-3)/(3a-2)用x表示y
答
x=(a-1+2)/(a-1)=(a-1)/(a-1)+2/(a-1)=1+2/(a-1)
2/(a-1)=x-1
a-1=2/(x-1)
a=2/(x-1)+1=(x+1)/(x-1)
2a-3=2(x+1)/(x-1)-3=(2x+2-3x+3)/(x-1)=(-x+5)/(x-1)
3a-2=3(x+1)/(x-1)-2=(3x+3-2x+2)/(x-1)=(x+5)/(x-1)
所以y=([(-x+5)/(x-1)]/[(x+5)/(x-1)]=(-x+5)/(x+5)