｛x÷7=y÷10=z÷5 ①｛x+2y+3z=84 ②

已知,方程组:4x-3y-7z=0 x+2y=10z 则(x-y+z)÷(x+y+z)=—— ｛x÷7=y÷10=z÷5 ①｛x+2y+3z=84 ② (x+y+z)÷10=x+1.1 y+x=z-80+y-1 z-y=8x+y+8 x+z÷y=? 已知4x-3y-6z=0 ① ,x+2y-7z=0 ②,且x,y,z均不为0,求3x+2y+z÷x+2y+3z的值 已知4x-3y-6z=0 ① ,x+2y-7z=0 ②,且x,y,z均不为0,求3x+2y+z÷x+2y+3z的值 已知：4x-3y-6z=0,x+2y-7z=0.求出x-y+z÷x+y+z=? 已知方程组{4x-3y-6z=0 x+2y-7z=0 且z≠0,则（x+y+3z）÷（4x-y-5z）=?结果和思路! 2x+3y-4z=-7,(x-4z)÷3=(2y+3z)÷2=2,求X,Y,Z的值 x/10=y/5=z/7 x+y+2z=29 求x y z (4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=? 已知4x-3y-6z=0,x+2y-7z=0,求5x+2y-z/2x-3y-10z x+y-z=0 x+2y-z=3 2x-3y+2z=5 y÷3-x+1÷6=3 2（x-y÷2))=3(x+y÷18) 4x+9y=12 3y-2z=1 7x+5z=19÷4 (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuaihuajian 已知x^2+4y^2-4x+4y+5=0,求(2x^2+xy-y^2分之x^4-y^4)乘以（xy-y^2分之2x-y)÷（y分之x^2+y^2)^2的值已知xyz≠0,x+3y+7z=0,3x-4y-18z=0,求(x^2+2y^2+8z^2)分之（3x^2+5y^2+6z^2)的值 (4x-2y-z)-{5x-[8y-2z-(x+y)]-2(3y-10z)}=?好难啊 已知1/x=5/y+z=3/z+x 求2xy/yz ÷x/Y的值 ①5x-4y+4z=132x+7y-3z=193x+2y-z=18②y=2x-75x+3y+2z=23x-4z=4