Question

Find the product AB, if possible.

Answer 1

A = f1q10g1.jpg
B = f1q10g2.jpg

Answer 2

Dont you know how to multiply a matrix on a vector?

Answer 3

no i forgot the sequence and I can't find it in my book

Answer 4

Do you know how to do a scalar multiplication of the vectors?

Answer 5

I think the answer is 29 and -39 I just don't know which way to put it

Answer 6

Yes, it is right. But i want you to remember how to multiply a matrix on a vector.

Answer 7

so is it 2(9) + -1(1) + 4 (3) = 29
and then -4(9) + (-9)(1) + 2(3)=-39

Answer 8

\[\left(\begin{matrix}a_{11} & a_{12} & a_{13} \\ a_{21} & a_{22} & a_{23}\end{matrix}\right)\cdot \left(\begin{matrix}b_{1} \\ b_{2} \\ b_{3}\end{matrix}\right)=\left(\begin{matrix}a_{11}b_1+a_{12}b_2+a_{13}b_3 \\ a_{21}b_1+a_{22}b_2+a_{23}b_3\end{matrix}\right)\]Please, note this rule somewhere.

Answer 9

so then they would go like this