7x-5y-23≤0x+7y-11≤04x+y+10≥0(1)求z=4x+3y的最值(2)求z=4x-3y的最值(3)求
7x-5y-23≤0x+7y-11≤04x+y+10≥0(1)求z=4x+3y的最值(2)求z=4x-3y的最值(3)求
已知x,y满足条件7x-5y-23≤ 0,x+7y-11≤ 0,4x+y+10 ≥0,求:z=4x-3y的最值
已知2x+3y-4z=0,3x+4y+5z=0,求x+y+z/(除以)x-y+z的值.
已知x::y:z=3:4:5,(1)求x+y分之z的值;(2)若x+y+z=6,求x,y,z.
已知x+4y+3z=3x-2y-5z=0,求x+2y-z/2x-3y+7z的值
已知4x-3y-6y=0,x+2y-7z=0.求x-y+z\x+y+z的值
已知x=3y,z=7y(x≠0),求代数式2x+3y-z分之x+y+z的值
已知3X-4Y-Z=0,2X+Y-8Z=0.求:(1)X+2Y-7Y的值.
已知方程组4x-3y-6z=0,x+2y-7z=0(z≠0),求x+y+3z/4x-y-5z的值
已知x=3y,z=7x(x不等于0),求代数式2x+3y-z分之x+y+z的值
已知3/x+y=4/x+y=5/y+z,求xyz/(x+y)(y+z)(z+x)的值
已知{3x+4y+5z=0,2x+3y-4z=0,求x+y+z/x-y+z的值.