
Doug C. answered 08/28/22
Math Tutor with Reputation to make difficult concepts understandable
Since M is the midpoint, it divides the segment LN into 2 equal parts. That means MN = 1/2 LN (or LN = 2 MN).
You have algebraic expressions for the length of MN and LN, so substitute those expressions and solve for x:
5x+16 = 2 (4x +6).
Solve that equation for x, then substitute that value into the expression for the measure of LN to get the final answer.