1.(15i + 14b + 13k) + (-30i-45j+51k) =

(15i +14b +13k) + (-30i-45j+51k)
=15i – 30i +14b+13k+51k-45j
=-15i + 14b + 64k -45j

Jawabannya 45i – 31b + 64k