Name Date
WORKSHEET 3.22: USING MATRICES — ADDITION,
SUBTRACTION, AND SCALAR MULTIPLICATION
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Matrices can be added, subtracted, or multiplied by a number called a scalar. Follow the
guidelines below:
- Two matrices can be added or subtracted only if they have the same number of rows
and columns. Add or subtract the corresponding elements. - To multiply a matrix by a scalar, multiply each element by the scalar.
EXAMPLES
A=
[
− 3 − 41
167
]
B=
[
− 176
248
]
A+B=
[
−43 7
31015
]
A−B=
[
− 2 − 11 − 5
− 12 − 1
]
4 A=
[
− 12 −16 4
42428
]
DIRECTIONS: Use these matrices to perform the indicated operations, if possible. If not
possible, write ‘‘impossible.’’
C=
[
− 34
68
]
D=
[
10
− 41
]
E=
[
01
38
]
N=
⎡
⎢
⎣
13
− 38
− 46
⎤
⎥
⎦ M=
⎡
⎢
⎣
16
73
49
⎤
⎥
⎦
- C+D 2. D+E 3. − 2 C 4. C−E
5. N+E 6. 3 N 7. M−N 8. M+C
CHALLENGE:Is it possible to add three or more matrices? Explain your
reasoning.
131
Copyright
©
2011 by Judith A. Muschla, Gary Robert Muschla, and Erin Muschla. All rights reserved.