ADDING AND SUBTRACTING MATRICES

Use matrices A, B, C and D to find the following.

Problem 1 :

A + B

Solution :

Combining corresponding terms, we get

Problem 2 :

D - B

Solution :

Problem 3 :

4C

Problem 4 :

6B - 2A

Solution :

Problem 5 :

3C - 4A + B

Solution :

Problem 6 :

C + 1/3D

Solution:

Problem 7 :

Use the following information. The Cookie Cutter Bakery records each type of cookie sold at three of their branch stores. Two days of sales are shown in the spreadsheets below.

a. Write a matrix for each day's sales.

b. Find the sum of the two day's sales expressed as a matrix.

c. Find the difference in cookie sales from Friday to Saturday expressed as a matrix.

Solution:

a.

Here rows are representing the sales done in three corresponding stores.

Columns are representing the variety of product they 

b.

c.