Answer:
b+3a
Step-by-step explanation:
MN=AN+AM
AN=0.5*AB
AB=OA+OB=4a+2b
AN=2a+b
AM=OA-OM=4a-3a=a
MN=2a+b+a=3a+b
MN = b - a
N = [tex]\frac{1}{2}[/tex]BA
BA = a - b = 4a - 2b
[tex]\frac{1}{2}[/tex]BA = [tex]\frac{1}{2}[/tex] (4a - 2b) = 2a - b
Thus
MN = MO + OB + [tex]\frac{1}{2}[/tex] BA
= - 3a + 2b + 2a - b
= b - a
