x-y
=(x-y)(x+y)/(x+y)
=(x²-y²)/(x+y)
=24/6
=4
与x+y=6 联立
2x=10
x=5
y=6-x=6-5=1
x+2y=5+2x1=7
如果本题有什么不明白可以追问,