Question

3

1
4
B=
1
2
A=
5
3
A. AB =
11
29
4
11
B. AB=
2
12
3
10
a
C. AB =
6
15
1
8
D. AB =
17
27
4
14

Answer 1

A

Explanation:

Sum the product of the components in the first row of A with the corresponding components of the first column in B

Repeat this with the components in the second row of A with the corresponding components of the second column in B, that is

AB

=
`\left[\begin{array}{ccc}2&1\\3&4\\\end{array}\right]`
`\left[\begin{array}{ccc}3&1\\5&2\\\end{array}\right]`

=
`\left[\begin{array}{ccc}2(3)+1(5)&2(1)+1(2)\\3(3)+4(5)&3(1)+4(2)\\\end{array}\right]`

=
`\left[\begin{array}{ccc}6+5&2+2\\9+20&3+8\\\end{array}\right]`

=
`\left[\begin{array}{ccc}11&4\\29&11\\\end{array}\right]` → A