若z^x=3,4^y=5,则2^x-2y的值为若2^x=3,4^y=5,则2^x-2y的值为

若x/2=y/3=z/4,则3x-2y+5z/x+y+z= 若x+y+z=3y=2z,则x/x+y+z=? 若x,y,z成等差数列,则(z-x)^2-4(x-y)(y-z)= 若x/2=y/3=z/4则3x-2y+5z/x+y+x= 若x,y,z成等差数列,则(z-x)^2-4(x-y)(y-x)= (4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=? 已知：4x-5y+2z=0 x+4y-3z=0则：(x*x+y*y+z*z)/(x*y+y*z+z*x)=____. 三元一次方程组题目x+y-z=11 y+z-x=5 x-y+z=1x+y=4 y+z=3 x+z=5若已知x-3y+2z=0 2x+3y-8z=0, 且xyz≠0,则x:y:z= 若x/4=y/4=z/5,则x+y/x-2y+3z= 若x/3=y/4=z/5则x+y/x-2y+3z=? 若2x+5y+4z=0 ,3x+y=0；则x+y-z=? 若x/3=y/2=z/5,则2x-3y-z/x-y+z= 若2x=3y=5z,则3x-2y+z/x+y-z 已知(x+2y)/3=(y+3z)/4=(z+5x)/5,则x:y:z= 已知x+2y/3=y+3z/4=z+5x/5,则x:y:z=? 已知x+2y/3=y+3z/4=z+5x/5,则x:y:z= 若4x=7y+5z,2x+y=z,则x:y:z的值为 已知方程组4x-5y+2z=0 x+2y=3z 则x:y:z