x+y=9 (100x+y)-(10y+x)=3[(10y+x)-(10x+y)] x+y=9 (100x+y)-(10y+x)=_数学解答

x+y=9 (100x+y)-(10y+x)=3[(10y+x)-(10x+y)]
x+y=9
(100x+y)-(10y+x)=3[(10y+x)-(10x+y)]
是二元一次方程啊

人气：264 ℃　时间：2020-05-31 05:46:07

解答

x+y=9(100x+y)-(10y+x)=3[(10y+x)-(10x+y)]
解得x=2y=7