00:01
Okay, let's say that you're given the matrix a, which is a three row by two column matrix, and matrix b, which is also a three row by two column matrix.
00:14
Okay, and let's say that you're asked to add a plus b.
00:18
Hey, the first thing you need to do before you can add matrices is to make sure that the matrix are the same dimension.
00:25
And in this case, they both are.
00:28
Okay, and then when you go to add, what you have to do, is just make sure you keep everything in its current position.
00:37
Okay, so we're going to first start with a, because that's what they start with.
00:40
So we're going to just rewrite this matrix.
00:45
Again, keeping everything in the correct row and column.
00:49
Now let's look at the b.
00:51
Okay, so again, i'm going to look at the first column first, and i'm just going to add on row one, add row two, add row three.
01:00
Okay, now let's look at the second column.
01:02
We're going to add that on, so i'm going to add row one, row two, row three.
01:11
Okay, and so when we add these together, we find our solution is 7, 2, 2, and then negative 4, 1, negative 1.
01:27
And what you're going to notice is your solution is also a 3 by 2, and that should stay the same.
01:35
Okay, so now let's try b plus a.
01:42
How we go about adding it is the same process...