Answer:
v See below. v
Step-by-step explanation:
LM = MN
11x - 21 = 8x + 15
[tex]3x-21=15\\3x=36\\[/tex]
x = 12
LM = 11(12) - 21 = 132 - 21 = 111
MN = 8(12) + 15 = 96 + 15 = 111
LN = 111 + 111 = 222