18.18 Mathematical methods and models in economics

Condition: Two types of vegetable oil of different quality are sold in three stores. Matrix \(A\) - sales volumes of these products in stores in the 1st quarter, matrix \(B-\) in the 2nd quarter. Determine: a) sales volume for two quarters; b) increase in sales in the 2nd quarter compared to the first. \[ A=\left(\begin{array}{ll} 3 & 4 \\ 6 & 4 \\ 2 & 3 \end{array}\right) ; B=\left(\begin{array}{ll} 1 & 2 \\ 5 & 3 \\ 3 & 3 \end{array}\right) \]