What is the step. some help

Answer:
Step-by-step explanation:
LM=2x+24
MN= x+28
LN=31
LN=(2x+24)+(x+28)
31=(2x+24)+(x+28)
solve
31=(2x+24)+(x+28)
31-24-28 = 2x +x
-21=3x
-7=x