若x+y+z=30,3x+y-z=50,x,y,z均为非负数,且m=5x+4y+2z,试求m的最大值与最小值.
来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/05/14 00:15:09
若x+y+z=30,3x+y-z=50,x,y,z均为非负数,且m=5x+4y+2z,试求m的最大值与最小值.
x+y+z=30 (1)
3x+y-z=50 (2)
5x+4y+2z=m (3)
(1)+(2)
4x+2y=80
2x+y=40 (4)
(2)*2+(3)
6x+2y+5x+4y=100+m
11x+6y=100+m (5)
(4)*6-(5)
12x+6y-11x-6y=240-100-m
x=140-m
y=40-2x=2m-240
z=30-x-y=130-m
因为x,y,z均为非负数
所以x>=0,y>=0,z>=0
140-m>=0,m=0,m>=120
130-m>=0,m
3x+y-z=50 (2)
5x+4y+2z=m (3)
(1)+(2)
4x+2y=80
2x+y=40 (4)
(2)*2+(3)
6x+2y+5x+4y=100+m
11x+6y=100+m (5)
(4)*6-(5)
12x+6y-11x-6y=240-100-m
x=140-m
y=40-2x=2m-240
z=30-x-y=130-m
因为x,y,z均为非负数
所以x>=0,y>=0,z>=0
140-m>=0,m=0,m>=120
130-m>=0,m
若x+y+z=30,3x+y-z=50,x,y,z均为非负数,且m=5x+4y+2z,试求m的最大值与最小值.
求一道初二数学题解法若x+y+z=9,3x+y-z=15,x,y,z均为非负数,求5x+4y+2z的最大值与最小值.求解
若X+Y+Z=30,3X+Y-Z=50,X,Y,Z均为非负数,求M=5X+4Y+2Z,m的取值范围.
已知x,y,z均为非负数,且3y+2z=x+3,3y+z=4-3x,W=3x+y+z,求W的最小值和最大值.
若x+y+z=30,3x+y-z=50,x、y、z皆为非负数,求M=5x+4y+2z的取值范围.
已知x,y,z为非负实数,且满足x+y+z=30,3x+y-z=50.求u=5x+4y+2z的最大值和最小值.
1.x+y+z=30,3x+y-z=50,x,y,z为非负数,求5x+4y+2z取值范围.
已知X Y Z都是非负数,且满足X+2Y-Z=1,2X+3Y-3Z=1,若有P=X+Y+Z,试求P的最大值和最小值
已知x+y+z=30,3x+y-z+50,x.y.z皆为非负数,求m=5x+4y+2z的取值范围.
已知x、y、z是非负数,且满足条件:x+y+z=30,3x+y-z=50,求w=5x+4y+2z的最大值和最小值
若X+Y+Z=30,3X+Y-Z=50 ,且x、y、z均为非负数,则M=X-Y-Z的取值范围:
已知x,y,z都为非负数,满足x+y-z=1,x+2y+3z=4,记W=3x+2y+z,求x的最大值和最小值