JAWABAN
SOAL 1
A x (A . B) = (2i + 4j) x (2i + 4j . 2i + j - 2k)
= (2i + 4j) x (4 + 0 - 0 + 0 + 4 - 0)
= (2i + 4j) x (8)
= 16i + 32j
JAWABAN
SOAL 2
A x B = (3i + 5j - 7k) x (2j + 5k)
= 6k + (-15j) + 0 + 25i + 14i - 0
= 6k - 15j + 39i / 39i - 15j + 6k
