Previous-year question practice database
Answer
Exam answer
From part (b):
B(A+C) = [[2,6],[4,12]]
From part (c):
5B = [[10,5],[20,10]]
Therefore:
B(A+C) − 5B
= [[2−10, 6−5], [4−20, 12−10]]
= [[−8,1], [−16,2]]
Answer:
[[−8,1],[−16,2]].
Explanation
Subtract corresponding entries of 5B from B(A+C).