Answer:
B. 4
Step-by-step explanation:
Since ,AB is the mid segment of triangle LMN
Then
[tex]\Longleftrightarrow AB=\frac{MN}{2}[/tex]
[tex]\Longleftrightarrow x+8=\frac{5x+4}{2}[/tex]
[tex]\Longleftrightarrow 2\times(x+8)=5x+4[/tex]
[tex]\Longleftrightarrow 2x+16=5x+4[/tex]
[tex]\Longleftrightarrow 16-4=5x-2x[/tex]
[tex]\Longleftrightarrow 3x=12[/tex]
[tex]\Longleftrightarrow x=\frac{12}{3}=4[/tex]
