已知x=(y-2)/(y+3) 用含的x代数式表示y

已知x=(y-2)/(y+3) 用含的x代数式表示y
已知x=(y-2)/(y+3) 用含的x代数式表示y

已知x=(y-2)/(y+3) 用含的x代数式表示y
x = 1 - 5/(y+3)
5/(y+3) = 1 - x
y+3= 5/(1-x)
故 y = 5/(1-x) -3 = (2+3x)/(1-x)

x=(y-2)/(y+3)=1-5/(y+3)
1-x=5/(y+3)
y=5/(1-x) -3

y=(2+3x)/(1-x)

xy+3x=y-2
xy-y=-3x-2
(x-1)y=-3x-2
y=(-3x-2)/(x-1)

x=(y-2)/(y-3) 乘过去得xy+3x=y-2 移项可得2+3x=y(1-x) 所以y=(2+3x)/(1-x)