问题
选择题
已知x+2y+3z=54,3x+y+2z=47,2x+3y+z=31,那么代数式x+y+z的值是( )
A.132
B.32
C.22
D.17
答案
三个式子相加得:(x+2y+3z)+(3x+y+2z)+(2x+3y+z)=54+47+31;
即6(x+y+z)=132;
解得:x+y+z=22.
故选C.
已知x+2y+3z=54,3x+y+2z=47,2x+3y+z=31,那么代数式x+y+z的值是( )
A.132
B.32
C.22
D.17
三个式子相加得:(x+2y+3z)+(3x+y+2z)+(2x+3y+z)=54+47+31;
即6(x+y+z)=132;
解得:x+y+z=22.
故选C.