ASK - ANSWER - COMMENT - VOTE - CREATE

Sites: Global Q&A | Wits | MathsGee Club | Joburg Libraries | StartUps | Zimbabwe | OER

MathsGee is Zero-Rated (You do not need data to access) on: Telkom |Dimension Data | Rain | MWEB

1 like 0 dislike
18 views

\text { If } A=\left[\begin{array}{cc}
1 & 3 \\
0 & 2 \\
-1 & 4
\end{array}\right] \text { and } B=\left[\begin{array}{cccc}
1 & 2 & 3 & -4 \\
2 & 0 & -2 & 1
\end{array}\right] \text { find } A B \text { . }
| 18 views

## 1 Answer

0 like 0 dislike
\begin{aligned}
A B &=\left[\begin{array}{ll}
1 & 3 \\
0 & 2 \\
-1 & 4
\end{array}\right]\left[\begin{array}{llll}
1 & 2 & 3 & -4 \\
2 & 0 & -2 & 1
\end{array}\right] \\
&=\left[\begin{array}{llll}
(1)(1)+(3)(2) & (1)(2)+(3)(0) & (1)(-4)+(3)(1) \\
(0)(1)+(2)(2) & (0)(2)+(2)(0) & (0)(-4)+(2)(1) \\
(-1)(1)+(4)(2) & (-1)(2)+(4) 0) & (-1)(-4) + (4)(1)
\end{array}\right] \\
&=\left[\begin{array}{llll}
7 & 2 & -3 & -1 \\
4 & 0 & -4 & 2 \\
7 & -2 & -11 & 8
\end{array}\right]
\end{aligned}
by Wooden (2,882 points)

0 like 0 dislike
1 answer
0 like 0 dislike
0 answers
0 like 0 dislike
1 answer
0 like 0 dislike
1 answer
0 like 0 dislike
1 answer
0 like 0 dislike
1 answer
0 like 0 dislike
1 answer
0 like 0 dislike
1 answer
0 like 0 dislike
1 answer
0 like 0 dislike
1 answer
0 like 0 dislike
1 answer
0 like 0 dislike
1 answer
0 like 0 dislike
0 answers
0 like 0 dislike
1 answer
0 like 0 dislike
1 answer
0 like 0 dislike
0 answers
0 like 0 dislike
1 answer
0 like 0 dislike
1 answer
0 like 0 dislike
1 answer
0 like 0 dislike
1 answer
0 like 0 dislike
0 answers
0 like 0 dislike
1 answer
0 like 0 dislike
0 answers
0 like 0 dislike
1 answer
0 like 0 dislike
0 answers
0 like 0 dislike
1 answer
0 like 0 dislike
0 answers
0 like 0 dislike
1 answer
0 like 0 dislike
0 answers
0 like 0 dislike
1 answer
0 like 0 dislike
0 answers
0 like 0 dislike
0 answers
0 like 0 dislike
1 answer
0 like 0 dislike
1 answer
0 like 0 dislike
0 answers
0 like 0 dislike
1 answer
0 like 0 dislike
1 answer
0 like 0 dislike
1 answer
0 like 0 dislike
1 answer
2 like 0 dislike
1 answer