How to Multiply Matrix? (+FREE Worksheet!)

Here is a step-by-step guide to multiply matrices. The exercises can help you measure your knowledge of matrix multiplication.

How to Multiply Matrix? (+FREE Worksheet!)

Related Topics

Step by step guide to multiply matrices

  • Step 1: Make sure that it’s possible to multiply the two matrices (the number of columns in the 1st one should be the same as the number of rows in the second one.)
  • Step 2: The elements of each row of the first matrix should be multiplied by the elements of each column in the second matrix.
  • Step 3: Add the products.

Matrix Multiplication – Example 1:

\(\begin{bmatrix}-5 & -5 \\-1 & 2 \end{bmatrix}\)\(\begin{bmatrix}-2 & -3 \\3 & 5 \end{bmatrix}\)

Solution:

Multiply the rows of the first matrix by the columns of the second matrix. \(\begin{bmatrix}(-5)(-2)+(-5)(3) & (-5)(-3)+(-5)(5) \\(-1)(-2)+(2)(3) & (-1)(-3)+(2)(5) \end{bmatrix}= \begin{bmatrix}(10)+(-15) & (15)+(-25) \\(2)+(6) & (3)+(10) \end{bmatrix}=\begin{bmatrix}-5 & -10 \\8 & 13 \end{bmatrix}\)

The Absolute Best Books to Ace Pre-Algebra to Algebra II

Matrix Multiplication – Example 2:

\(\begin{bmatrix}-4 & -6&-6 \\0 & 6&3 \end{bmatrix}\begin{bmatrix}0 \\-3 \\0 \end{bmatrix}\)

Solution:

Multiply the rows of the first matrix by the columns of the second matrix. \(\begin{bmatrix}(-4)(0)+(-6)(-3)+(-6)(0) \\(0)(0)+(6)(-3)+(3)(0) \end{bmatrix}=\begin{bmatrix}0+18+0 \\0-18+0 \end{bmatrix}=\begin{bmatrix}18 \\-18 \end{bmatrix}\)

Matrix Multiplication – Example 3:

\(\begin{bmatrix}1 & 3 \\2 & 4 \end{bmatrix}\)\(\begin{bmatrix}2 &4 \\-2 & 1 \end{bmatrix}\)

Solution:

\(\begin{bmatrix}(1) (2)+(3)(-2) & (1) (4)+(3) (1) \\(2) (2)+ (4)(-2) & (2) (4)+(4) (1) \end{bmatrix}=\begin{bmatrix}(2)+(-6) & (4)+(3) \\(4)+ (-8) & (8)+(4) \end{bmatrix}=\begin{bmatrix}-4 & 7 \\-4 & 12 \end{bmatrix}\)

The Best Book to Help You Ace Pre-Algebra

$14.99
Satisfied 92 Students

Matrix Multiplication – Example 4:

\(\begin{bmatrix}2 & -1&-1 \\3 & 1&5 \end{bmatrix}\begin{bmatrix}-2 \\-1 \\4 \end{bmatrix}\)

Solution:

Multiply the rows of the first matrix by the columns of the second matrix. \(\begin{bmatrix}(2)(-2)+(-1)(-1)+(-1) (4)\\(3)(-2)+(1)(-1)+(5) (4) \end{bmatrix}=\begin{bmatrix}(-4)+(1)+(-4)\\(-6)+(-1)+(20) \end{bmatrix}=\begin{bmatrix}-7 \\13 \end{bmatrix}\)

Exercises for Multiplying Matrix

Solve.

  1. \(\color{blue}{\begin{bmatrix}0 & 2 \\-2 & -5 \end{bmatrix}\begin{bmatrix}6 & -6 \\3 & 0 \end{bmatrix}}\)
  2. \(\color{blue}{\begin{bmatrix}3 & -1 \\-3 & 6\\-6&-6 \end{bmatrix}\begin{bmatrix}-1 & 6 \\5 & 4\end{bmatrix}}\)
  3. \(\color{blue}{\begin{bmatrix}0 & 5 \\-3 & 1\\-5&1 \end{bmatrix}\begin{bmatrix}-4 & 4 \\-2 & -4\end{bmatrix}}\)
  4. \(\color{blue}{\begin{bmatrix}5 & 3&5 \\1 & 5&0 \end{bmatrix}\begin{bmatrix}-4 & 2 \\-3 & 4\\3&-5 \end{bmatrix}}\)
  5. \(\color{blue}{\begin{bmatrix}4 & 5 \\-4 & 6\\-5&-6 \end{bmatrix}\begin{bmatrix}4 & 6 \\6& 2\\-4&1 \end{bmatrix}}\)
  6. \(\color{blue}{\begin{bmatrix}-2 & -6 \\-4 & 3\\5&0 \\4&-6\end{bmatrix}\begin{bmatrix}2 & -2&2 \\-2 &0&-3 \end{bmatrix}}\)
  1. \(\color{blue}{\begin{bmatrix}6 & 0 \\-27 & 12 \end{bmatrix}}\)
  2. \(\color{blue}{\begin{bmatrix}-8 & 14 \\33 & 6\\ -24&-60\end{bmatrix}}\)
  3. \(\color{blue}{\begin{bmatrix}-10 & -20 \\10 & -16\\ 18&-24\end{bmatrix}}\)
  4. \(\color{blue}{\begin{bmatrix}-14 & -3 \\-19 & 22 \end{bmatrix}}\)
  5. \(\color{blue}{Undefined}\)
  6. \(\color{blue}{\begin{bmatrix}8 & 4&14\\-14 & 8&-17\\10&-10&10 \\20&-8&26\end{bmatrix}}\)

The Greatest Books for Students to Ace the Algebra

Related to This Article

What people say about "How to Multiply Matrix? (+FREE Worksheet!) - Effortless Math: We Help Students Learn to LOVE Mathematics"?

No one replied yet.

Leave a Reply

X
45% OFF

Limited time only!

Save Over 45%

Take It Now!

SAVE $40

It was $89.99 now it is $49.99

The Ultimate Algebra Bundle: From Pre-Algebra to Algebra II