Can someone me out with #5 and if you can’t explain yourself don’t comment.

We'll do a little construction here, and for that I'm gonna suppose it's a trapezium.

Join B and D and.
now as you can see in the picture above,

as the line having y and z measured 17 therefore,

y+z = 17

Now,
as the line y is || to AB (I've supposed it's a trapezium)

Therefore,
by mid point theroem,

2(y)=5
y = 2.5

Now, by susbtituting this value in y+z =17
you'll get

2.5 + z = 17
z = 14.5

Now, in triangle BDC

by mid point theorem,

2(z)= x

we already know the value of z so simply substitute it and you'll end up with,

2(14.5) =x
29 = x.

Therefore,
option B is the correct one.