Question

A=[ 7 -5;
5 -9]
B= [ -8 4;
6 -8]

What is AB??

Answer 1

\[A=\left(
\begin{array}{cc}
7 & -5 \\
5 & -9
\end{array}
\right),B=\left(
\begin{array}{cc}
-8 & 4 \\
6 & -8
\end{array}
\right)\]

Answer 2

First row * First column
7*-8 + -5*6 =-86

Answer 3

\[\left(
\begin{array}{cc}
-86 & \square \\
\square & \square
\end{array}
\right)\]

Answer 4

Now for second one.
first row * second colum
7*4 +-5*-8=68
\[\left(
\begin{array}{cc}
-86 & 68 \\
\square & \square
\end{array}
\right)\]

Answer 5

can you do the last two?

Answer 6

yes i think so, thank you!