Question

Explain please????

Answer 1

-5 A means multiply every number in A by 5
4 B means multiply every number in B by 4

Answer 2

then add the two matrices (add corresponding elements)

Answer 3

so D?.. sorry took me a while.. lol

Answer 4

how do i do this one?

Answer 5

@whpalmer4

Answer 6

@johnweldon1993

Answer 7

Same way as the other one, I think.

Multiply 2 with each element in the known array that you have there. Then figure out what you would have if you take the array on the right, and subtract the corresponding element of the array you just created. That will create an array that has the values of 2X. Now divide each element by 2 to get the values of X, right?

Answer 8

That would be correct @whpalmer4

Answer 9

And yes, I agree with D for the answer for the first problem.

Answer 10

Soyes @rileymarie6666 ...multiply each element in that matrix by 2.....then subtract that matrix from the one on the right....and finally divide the resulting matrix by 2 to solve for 'x'

Answer 11

i dont get it...

Answer 12

so we have

\[\large 2x + 2\left[\begin{matrix}2 & -8 \\ -4 & 2 \end{matrix}\right] = \left[\begin{matrix}4 & -6 \\ 2 & -8\end{matrix}\right]\]

First multiply that first matrix by 2 ...

\[\large 2x + \left[\begin{matrix}4 & -16 \\ -8 & 4 \end{matrix}\right] = \left[\begin{matrix}4 & -6 \\ 2 & -8\end{matrix}\right]\]

Now subtract that matrix from both sides

\[\large 2x = \left[\begin{matrix}4 & -6 \\ 2 & -8\end{matrix}\right] - \left[\begin{matrix}4 & -16 \\ -8 & 4 \end{matrix}\right]\]

Subtract each element

\[\large 2x = \left[\begin{matrix}0 & 10 \\ 10 & -12\end{matrix}\right]\]

And finally divide each element by 2 to solve for 'x'

\[\large x = \left[\begin{matrix}0 & 5 \\ 5 & -6\end{matrix}\right]\]

Answer 13

okay cool. and for this one i am getting irritated. I got 43 for the top left and 45 for the top right... but clearly thats wrong...

Answer 14

the way i did it was -5*-5+-2*-9= 43 and -5*7+-2*-5

Answer 15

So we have

\[\large \left[\begin{matrix}-5 & -2 \\ -8 & -5\end{matrix}\right]\left[\begin{matrix}-5 & 7 \\ -9 & -5\end{matrix}\right]\]


...well yes what you are doing is correct

\(\large (-5 \times -5) + (-2 \times -9) = 25 + 18 = 43\) so this is correct
However
\[\large \color \red{(-5 \times 7) + (-2 \times -5) = -35 + 10 = -25}\]

Answer 16

ohhh so would this answer be B...? would the bottom left be 85?

Answer 17

Indeed it would :)

Answer 18

@Nurali

Answer 19

i just need help with 4 and 5 please