已知x^2-3xy-10y^2=0,且y不等于0,则x/y的值为?

问题描述:

已知x^2-3xy-10y^2=0,且y不等于0,则x/y的值为?

先因式分解(x-5y)(x+2y)=0
x=5y或x=-2y
又y不等于0
所以
x/y=5 或 x/y=-2

式子可化x(x-3y)=10y^2,即y/x=(x/10y)-3/10,化解行x/y为5或-2

x^2-3xy-10y^2= (x-5y)(x+2y)=0
x-5y=0 or x+2y=0.
x/y = 5 or x/y = -2

5和-2
(x/y)^2-3x/y-10=0,
(x/y-5)(x/y+2)=0

(x-5y)(x+2y)=0
x=5y 或x=-2y
x/y=5 或-2

x^2-3xy-10y^2=0
(x+2y)(x-5y)=0
x+2y=0或x-5y=0
因为:y不等于0
所以 x/y=-2 或 x/y=5