Question

xy/x+y=20 and yz/y+z=40 and zx/z+x=24

Answer 1

x+y/xy = 1/20
y+z/yz = 1/40
z+x /zx = 1/24
so,{(x+y)z + (y+z)x + (z+x)y }/xyz = 1/20+1/40+1/24
=( xz +yz +xy+xz +yz + xy)/xyz = 6+3+5/120
= 2(xy+yz+zx) /xyz = 14/120
= (xy+yz+zx)/xyz = 7/120