If

O
N

=

8
x



8
,

L
M

=

7
x

+

4
,

N
M

=

x



5
,
and
O
L

=

3
y



6
,
find the values of x and y for which LMNO must be a parallelogram.

In a parallelogram, opposite sides are equal in length. Therefore, we can set up two equations:

ON = LM
8x - 8 = 7x + 4
x = 12

OL = MN
3y - 6 = 12 - 5
3y = 11
y = 11/3

Therefore, the values of x and y for which LMNO must be a parallelogram are x = 12 and y = 11/3.