Previous-year question practice database
Answer
Exam answer
From part (a):
A + C = [[−4,3],[10,0]]
B = [[2,1],[4,2]]
B(A+C)
= [[2,1],[4,2]] [[−4,3],[10,0]]
= [[2(−4)+1(10), 2(3)+1(0)], [4(−4)+2(10), 4(3)+2(0)]]
= [[2,6], [4,12]]
Answer:
[[2,6],[4,12]].
Explanation
Use the result of part (a), then multiply B by A+C row by column.