Your answer is 70.
As this is a parallelogram, lines PN and MO are the same length. This also means K is the midpoint of line PN. From this, you can deduce that PK = KN as both are half of line PN
So, equating the expressions gives
And now we have to rearrange and solve for x by factorising
Now, if we substitute both values into PK =5x, we know that x cannot be - 2, as we cannot have a negative length.
Using x = 7 and substituting
Then multiplying by 2 to give the entire length of PN