Question

x;y;z khac 0 va x-y-z=0 . tinh B=(1-  z/x).(1-  x/y).(1+y/z) 

Answer 1

x-y-z=0

=> x=y+z

     y=x-z

    -z=y-x

B=(1-z/x)(1-x/y)(1+y/z)

B=((x-z)/x)((y-x)/y)((z+y)/z)

B=(y/x)(-z/y)(x/z)

B=(-z.y.x)/(x.y.z)

B=-1