5x+3y+2z=2011 4x+6y+7z=2012 求x+y+z
问题描述:
5x+3y+2z=2011 4x+6y+7z=2012 求x+y+z
答
(5x+3y+2z)+(4x+6y+7z)=2011+2012
9(x+y+z)=4023
x+y+z=447