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x+2y+3z=105x+4y+3z=8x+y+z=

题目详情
x+2y+3z=10 5x+4y+3z=8 x+y+z=
▼优质解答
答案和解析
答案:3
另A=x+y+z,另B=y+2Z分别带入上述两式
得:
x+2y+3z=10 => x+y+z +y+2z=10 => A+B=10 ----(3)
5x+4y+3z=8 => 5(x+y+z)-(y+2z)=8 => 5A-B=8 ----(4)
(3)式加(4)式,得:6A=18 => A=x+y+z=3