In this problem LN would be equal to 38.
In order to find this, we need to first note that LM will be half of LN (since M is the midpoint). As a result, we can multiply LM by 2 and set it equal to LN.
2LM = LN
2(2x + 7) = 3x + 20
4x + 14 = 3x + 20
x + 14 = 20
x = 6
Now that we have the value of x as 6, we can plug into LN to get it's value.
LN = 3x + 20
LN = 3(6) + 20
LN = 38