ABCD is a parallelogram. The diagonals of ABCD intersect at O.
B
b)
b.
OA=a
and
OB = b
c)
o
a) Express the vector CA in terms of a.
a
А
D
b) Express the vector AB in terms of a and b.
c) Express the vector BC in terms of a and b.

for this case we must apply distributive property to the following expression:

the distributive property states that:

then, when applying the property we have to multiply the -2 for each term within the parenthesis:

the absolute value function

his answer is incorrect. i just used it, and it said it was incorrect. the answer is 0.