Respuesta :

Answer:

a) CD = 6a + 4.5b

b) k = 4

Step-by-step explanation:

CD = CA + AB

CA = -AC

CD = -3b + 6a + 7.5b

CD = 6a + 4.5b

BC is parallel to CD

BC = BA + AC

BC = ka + 3b

BC is a scalar multiple of CD

Scale factor:

3/4.5 = 2/3

k = ⅔(6)

k = 4