已知3x-2y-5z=0,2x-5y+4z=0,且x.y.z均不为0,求3x^2+2y^2+5z^2/5x^2+y^2-

来源：学生作业帮编辑：大师作文网作业帮分类：数学作业时间：2024/11/12 04:48:22

已知3x-2y-5z=0,2x-5y+4z=0,且x.y.z均不为0,求3x^2+2y^2+5z^2/5x^2+y^2-9z^2的值

3x-2y-5z=0 12x-8y-20z=0
2x-5y+4z=0 10x-25y+20z=0
两式相加
22x-33y=0
22x=33y
y=2/3x
3x-2y-5z=0 15x-10y-25z=0
2x-5y+4z=0 4x-10y+8z=0
两式相减
11x-33z=0
11x=33z
z=1/3x
3x^2+2y^2+5z^2/5x^2+y^2-9z^2
=(3x^2+8/9x^2+5/9x^2)/(5x^2+4/9x^2-x^2)
=(40/9)/(40/9)
=1

已知3x-2y-5z=0,2x-5y+4z=0,且x,y,z均不为0,求3x*x+2y*y+5z*z/5x*x+y*y- 已知3x-2y-5z=0,2x-5y+4z=0,且x,y,z都不为0,求（3x*x+y*y+4z*z）/（5x*x+y* 已知x,y,z均不为0,且满足方程组x+y-z=0,2x-y-5z=0试求2x+y+3z/3x-y-z 已知x,y,z均不为0,且满足方程组{x+y-z=0,①2x-y-5z=0.②试求(2x+y+3z)/(3x-y-z)值已知3x-2y-5z=0,2x-5y+4z=0,且x.y.z均不为0,求3x^2+2y^2+5z^2/5x^2+y^2- 已知3x-2y-5z=0,2x-5y+4z=0,且x,y,z均不为0,求3x平方+2y平方+5z平方/5x平方+y平方- 已知x,y,z均不为0,且满足方程组x+y-z=0,①2x-y-5y=0.②试求2x+y+3z/3x-y-z值. 已知x+4y+3z=3x-2y-5z=0,求x+2y-z/2x-3y+7z的值已知{3x+4y+5z=0,2x+3y-4z=0,求x+y+z/x-y+z的值. 已知2x+3y-4z=0,3x+4y+5z=0,求x+y+z/（除以）x-y+z的值. 已知2x+3y-4z=0,3x+4y+5z=0,求x+y+z/x-y+z的值. 已知3x+4y+5z=0,2x+3y-4z=0,求(x+y+z)/(x-y+z)