在代数式1/2x-y,5a,x的2次方-y+2/3,1/兀,x,y,z,-5/y,x+y+z/3,有几个整式

在代数式1/2x-y,5a,x的2次方-y+2/3,1/兀,xyz,-5/y,x+y+z/3,有几个整式 1.（x+y-z)+(x-y+z)-(x-y-z) 2.2x-(3x-2y+3)-(5y-2) 若有理数x,y,z满足(x-1)的2016次方+|2x-y|+lx-3z|=0,求3x-5y-9z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. x/2=y/3=z/5 x+3y-z/x-3y+z {(z+y)(x-y)-(x-y)的2次方+2y(x-y)}除以4y {x+y+z=1;x+3y+7z=-1;z+5y+8z=-2 若4x-3y-6z=0,x+2y-7z=0,求代数式5x*5x+2y*2y-z*z/2x*2x-3y*3y-10z*10 x+y+z=2 x-3y+2z=1 2x+2y+z+5 要具体步骤.. 3x+2y+z=14 ,x+y+z=10,z+2x+3y=1 5 {5x-3y+z=2{5x+2y-4z=3{-5x+y-z=2 {x-y-z=-1{3x+5y+7z{4x-y+2x=- 已知2x+3y-4z=0,3x+4y+5z=0,且xyz≠0 .(1)分别用含有z的代数式表示x、y (2)求x+y+z