Question

已知3x-2y-5z=0,x+2y+-7y=0 且xyz 不等于0求(x*x-2y*y+z*z)/yz

Answer 1

3x-2y-5z=0,x+2y+-7y=0

x=5y,z=(13/5)y

(x*x-2y*y+z*z)/yz =(25y*y-2y*y+(13/5)*(13/5)y*y)/((13/5)y*y)

=744/65