Question

Explain to me how to solve this question (dont give answer)

Find 6a - 5b

A = [-3,7,1_9,8,-5] B = [ -4,3,-9_3,7,6]

Answer 1

plug away

Answer 2

Like -3 - -4 or multiply it

Answer 3

Im not really sure

Answer 4

Both A and B are matrices with 2 rows and 3 columns.

if you write nA where n is a number, that is short hand for "multiply every element in A by n"

you can add two matrices if they are the same shape. (as in this case)
to add matrices, add corresponding elements. The answer is a new matrix, the same shape as the ones you started with.

Answer 5

for 6A -5B you can treat it as 6A + -5B or as 6A - 5B

Answer 6

Ok so do I multiply subtract add or divide to find the answer?

Answer 7

The first step is multiply: 6A means multiply every number in A by 6
do the same for -5B : multiply every element in B by -5

then add the two matrices that you get from the first step

so you use multiply in step 1 and add in step 2

Answer 8

So the new matrix it [2,-17,51_39,3,-60]?

Answer 9

I checked 2 and 39 and they are correct.
so unless you goofed on the arithmetic on the other numbers, it looks good.

Answer 10

sorry 17 is supposed to be 27 correct? and 3 is supposed to be 13 sorry

Answer 11

2 27 51
39 13 -60