LN = 120 and a = 10
Step-by-step explanation:
If we need to find the variable a as, LN is the line and M is the mid point between L and N. So LN = LM + MN
LM = 4a = 40
a = [tex]\frac{40}{4}[/tex] = 10
MN = 8a = 8×10 = 80
So LN = LM + MN
LN = 40 + 80 = 120