(a) a+b+c=

10i-19j-7k

(b) a-3b=

-2i-5j-7k-3(4i-11j)=

-14i-38j-7k

c) You try it, as it is your exercise

d) a*b=-8i+55j

e) axc=

| i....j....k |

|-2.-5.-7 |

| 8.-3..0. |

=-21i-56j+46k

a) 10i -19j -7k

b) -14i +28j -7k

c) -8.66i +1.35j -2.31k

d) 47

e) -21i - 56j + 46k