已知x+y-z=0,2x-y+2z=0 求(3x-2y+5z)/(5x-3y+2z)的值

问题描述:

已知x+y-z=0,2x-y+2z=0 求(3x-2y+5z)/(5x-3y+2z)的值

由x+y-z=0,2x-y+2z=0可得:
z=-3x y=-4x
则3x-2y+5z/5x-3y+2z
=3x+8x-15x/5x+12x-6x
=-4x/11x
=-4/11