00:02
So to do this multiplication, we're going to know what kind of matrix we're dealing with.
00:08
So this is a 2 by 3 matrix.
00:13
What that means is that we have two rows, yeah, two rows, and then three columns, right? if you come to d, this is a 3 by 3 matrix.
00:26
So you have 3 rows and 3 columns.
00:29
So when you multiply a matrix, you want to have an idea as to what you're going to get as a follow answer, right? so anytime you are multiplying two matrices, you're going to take the first one here, the last one there.
00:45
That's going to 2 by 3.
00:47
So this way you're going to end up with.
00:49
So this is a 2 by 3 matrix.
00:51
So let's go ahead and do this and see what we're going to get.
01:00
All right.
01:01
So we're going to do row times column.
01:03
So you always do row times column and that's going to give you a row.
01:07
We're going to take this row right here we're going to take this row in multiple by this column you take that same row in one by that column is going to give you a row so let's see how that works so we take four multiple by two so that's four times the other number there two that gives you eight plus then we take six multiple by the second number so six times nine it's 54 we'll take five times 0 that gives it 0 so we're down in the first part so you take the same rule we multiply with the next column with the 4 times negative 3 that's negative 12 we got 6 times 3 that's 18 you got 5 times 8 that's 40 that is done go to the next part the same row in the next column so that 4 times 12 that's 48 6 times 1 that is six we got five times negative 10 that's negative 50 so we're done with that roll we take the next row we must go up by the whole column let's see how that goes so you have negative 8 times 2 that's negative 16 plus we got zero times 9 that gives 0 plus we got 11 times 0 that gives 0 and we move to the next column you have negative negative 8 times negative 3 that's 24 plus 0 times 3 0 you have 11 times 8 that's 88 we move to the last which is negative 8 times 12 that is negative 96 plus 0 plus 0 plus 11 times that's negative 110 so this is what we got so 5 finally, it's going to add everything up...