Answer:
 The value of x = 11  and y = 2
Step-by-step explanation:
 Given : parallelogram LMNO, MP = 21 m, LP = (y + 3) m, NP = (3y – 1) m, and OP = (2x – 1) m.
We have to find values of x and y.
Let P be the point of intersection of diagonals OM and LN.
In a parallelogram diagonal  bisects at right angles  and point of intersection divide diagonal in equal parts.
Thus, OP = MP and LP = PN 
OP = MP , substitute the values, we get,
(2x-1) =  21 
 ⇒ 2x = 22 
⇒  x = 11 
LP = PN , substitute the values, we get,
y + 3 = 3y -1 
⇒  3y - y = 4 
⇒  2y = 4 
⇒ y = 2   
Thus, the value of x = 11  and y = 2