WOLFRAM|DEMONSTRATIONS PROJECT

Multiplying a Matrix by a Number

​
rows
1
2
3
4
5
columns
1
2
3
4
5
new number, matrix
k = -2,
A =
2
2
-4
2
0
-4
-2
1
-3
5
1
2
k × A =
-2 × (2)
-2 × (2)
-2 × (-4)
-2 × (2)
-2 × (0)
-2 × (-4)
-2 × (-2)
-2 × (1)
-2 × (-3)
-2 × (5)
-2 × (1)
-2 × (2)
=
-4
-4
8
-4
0
8
4
-2
6
-10
-2
-4
To multiply a matrix by a number, multiply each entry by the number.
If there is only one column or only one row, the matrix is a column or a row vector.