初中数学题,帮帮忙啦
3х+7у+z=5,4х+10у+z=3求х+у+z的值
参考答案:3x+7y+z=5...(1)
4x+10y+z=3..(2)
(1)*3,9x+21y+3z=15...(3)
(2)*2,8x+20y+2z=6....(4)
(3)-(4),x+y+z=9
3х+7у+z=5,4х+10у+z=3求х+у+z的值
参考答案:3x+7y+z=5...(1)
4x+10y+z=3..(2)
(1)*3,9x+21y+3z=15...(3)
(2)*2,8x+20y+2z=6....(4)
(3)-(4),x+y+z=9