17.5 Properties of determinants 489
(17.40)
- Multiplication by a constant
If all the elements of any row (or column) are multiplied by the
same factor λ, the value of the new determinant is λtimes the
value of the old determinant:
(17.41)
EXAMPLE 17.10Examples of Property 2.
A special case isλ 1 = 10 : if all the elements of a row (or column) are zero, the value of
the determinant is zero:
(17.42)
- Addition rule
If all the elements of any row (or column) are written as the sum
of two terms the determinant can be written as the sum of two
determinants:
(17.43)
ad b c
ad bc
ad b c
abc
abc
ab
11
11
22
22
33
33
1
11
222
3
=
333
1
11
222
333
c
dbc
dbc
dbc
000
0
2 22
332
abc
abc
=
=×× 223 =××× =
111
143 2233
111
143
123
144
369
246 2
8
12
3
9
27
189
31227
2
13
19
327
22
11
14
36
==×
λλλ
λ
abc
abc
abc
abc
abc
abc
1
11
222
333
1
11
222
333
=
abc
abc
abc
aaa
bbb
ccc
1
11
222
333
1
23
123
123
=