Question

已知x平方—7xy+12y平方=0（y不等于0），求x-y/x+2y值,谢谢

Answer 1

x²-7xy+12y²=0
(x-3y)(x-4y)=0
x=3y或x=4y
x=3y时，
(x-y)/(x+2y)=(3y-y)/(3y+2y)=(2y)/(5y)=2/5
x=4y时，
(x-y)/(x+2y)=(4y-y)/(4y+2y)=(3y)/(6y)=1/2请点击采纳为答案