Final answer:
The variable a equals 25, and the length of LN is 150. The correct answer was not provided in the options, as the length calculation results in a value not listed.
Step-by-step explanation:
To find the value of the variable a and the length of LN, we need to use the given information. We have LM = 2a, which is given as 50, so we can write:
2a = 50
We divide both sides by 2 to find the value of a:
a = 25
Next, we find the length of MN using the value of a:
MN = 4a = 4(25) = 100
Since M is between L and N, LN = LM + MN, which means:
LN = 50 + 100 = 150
The correct value for a should be 25 and LN should be 150.