a/b=c/d=e/f=2
a=2b
c=2d
e=2f
(a+c+e)/(b+d+f)
=(2b+2d+2f)/(b+d+f)
=2(b+d+f)/(b+d+f)
=2
(a-5e)/(b-5f)
=(2b-5*2f)/(b-5f)
=2(b-5f)/(b-5f)
=2