3x+4y+5z=3.3和x+y+z=51和3x/5+y+5z/3=53.4帮我解一下方程组,

(x+y):(y+z):(z+x)=3:4:5 3x+y-z=-4已知(x+y):(y+z):(z+x)=3:4:5 ；3x+y-z=-4求x y z 解方程组x+y=5和y+z=3和z+x=4 C语言if语句和if… else语句技巧当x=3,y=4,z=5时,xyz值分别为多少.1.if（x>z）{x=y;y=z;z=x;} else{x=z;z=y;y=x} x,y,z值 2..if（x>z) x=z; else x=z;z=y;y=x ; x,y,z值 3.if（x!>z) x=z; else x=z;z=y;y=x ; x,y,z值 各自有什么区别? (4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=? 已知x/3=y/5=z/4,求x+y+z/y和x+y-z/y-x的值 已知x/3=y/5=z/4,求x+y+z/y和x+y-z/y-x的值,2种方法.急等. x+y-z=3 y+z-x=5 z+x-y=7 求x,y,z 若X:Y:Z=5:6:7那么(Y-X):(Y+Z)和(X+2Y+3Z):(3X+2Y+Z) x/2=y/3=z/5 x+3y-z/x-3y+z 设|x|-|y|+|z|=|x+y+z|,且|x+y|=4,|y+z|=5,|y|=3,求(x-y-z)^2的值 (4x-2y-z)-{5x-[8y-2z-(x+y)]-2(3y-10z)}=?好难啊 已知方程组3x+5y+3z=0,3x-5y-8z=0,并且z≠0,求x:z和y:z x+y=5 2x+3y-z=9 x-y+z=4 已知3X=4X,5Y=6Z求X+Y：Y+Z 已知x-y/x+y=y+z/2(y-z)=z+x/3(z-x),求证8x+9y+5z=0THX.. 一只x/3=y/4=z/5,求x+y+z/x及x+y+z/x-y+z的值 已知：4x-5y+2z=0 x+4y-3z=0则：(x*x+y*y+z*z)/(x*y+y*z+z*x)=____. 已知(x+2y)/3=(y+3z)/4=(z+5x)/5,则x:y:z=