Answer
See answers below.
Work Step by Step
Need to find parts a,b,c,d as follows:
(a) $7(-j)=-7j$
(b) $\sqrt 2(-\dfrac{3}{5}i-\dfrac{4}{5}k)=-\dfrac{3 \sqrt 2}{5} i -\dfrac{4 \sqrt 2}{5}k$
(c) $\dfrac{13}{12}(\dfrac{3}{13}i-\dfrac{4}{13}j-\dfrac{12}{13}k)=\dfrac{3}{12}i-\dfrac{4}{12}j-1k=\dfrac{1}{4}i-\dfrac{1}{3}j-k$
(d) $a(\dfrac{1}{\sqrt 2}i+\dfrac{1}{\sqrt 3}j -\dfrac{1}{\sqrt 6}k)=\dfrac{a}{\sqrt 2}i+\dfrac{a}{\sqrt 3}j -\dfrac{a}{\sqrt 6}k$
