Respuesta :

LMNO is a parallelogram
so NM = OL
x + 15 = 3x + 5
solve for x
x - 3x = 5 - 15
-2x = -10
   x = 5

Answer
x = 5
Since LMNO is a parallelogram all the sides are equal so if you take 3x+5 and  x+15 youll find that if you replace x with 5 on each side youll end up with 20 total on both sides therefore your answer is x equals 5.