00:01
So for this question, we're given these two matrices.
00:04
So we have matrix a, which represents the number of air conditioning units that a company has sold in the last year.
00:16
Or sorry, a number of air conditioning units, electric heaters, and humidifiers.
00:20
As with these three numbers represent that the company is sold in the past year.
00:24
And we're also given this matrix b, which represents how much money each of those single units cost.
00:30
An air humidifier, an air conditioner cost $120, a heater cost $695, and then finally a humidifier cost $6 .56 per unit.
00:45
So we are asked to calculate the product of matrix a times matrix b.
00:52
So the way we calculate that is we can go ahead and rewrite those matrices.
00:57
We get rid of the commas.
01:00
There so you have 235, 562, and 117, and that is being multiplied with 12695 and 656.
01:14
So as we talked about matrix multiplication is actually when you take each row in the matrix, right, and you multiply by each column, and luckily we have one row which has three values, and we have one column which also has three values.
01:29
So this matrix multiplication works...