若x+2y+4z=62x+y−z=9
若x+2y-4z=0 3x+y-z=0 求x:y:z
x=y/z=z/3,x+y+z =12,求2x+3y+4z是多少,
己知x,y,z,t满足方程组x+y+z=62x−z+t=−2
十万火急!4x-9z=17 3x+y+15z=18 x+2y+3z=
x+y−2z=52x−y+z=42x+y−3z=10
2x+y+3z=383x+2y+4z=564x+y+5z=66
解方程组x−4y=0x+2y+5z=22x+y+z=12
若x+y+z=303x+y−z=50,x、y、z均为非负整数,则M=5x+4y+2z的取值范围是( )
若实数x、y、z满足2|x−y|+2y+z+z
3x+4z=7①2x+3y+z=9 ②5x−9y+7z=8 ③
x+3y+4z=3x+5y+9z=25x−9y−3z=−10
解方程组:5x−4y+4z=132x+7y−3z=193x+2y−z=18