plz heelp

first, the whole distance is 32, which is XZ.

then, write algebraic equation, XY+YZ = XZ, 3n + n+16 = 32

combine like terms: 4n = 16

n = 4 

and XY = 4*3 = 12

xy+yz=zx

3n + n+16 = 32

4n = 16

n=4

xy=3n=3*4=12

Very simple way °