HELP PLZZ
I WILL CROWN BRAINLIEST
Just one simple question

Answer:
i) OC=a+b
ii) BA=a-b
iii)CA=-b
Step-by-step explanation:
i) because it is a parallelogram AC=OB and therefore AC=b
to find OC you do OA+AC which is a+b
OC=a+b
ii) to find BA you do BO+OA
BO=-b as it is the opposite direction
OA=a
so therefore BA=a-b
iii)CA is the opposite of AC which was b so CA=-b