December 20, 2005
105
DZ
121
!
25%
12
!1 × 12, 2 × 6, 3 × 4
!!
12 − 1 = 11, 6 − 2 = 4, 4 − 3 = 1.
3 × 4
!3 × 4
12
!!F 12 = 3 424
1 × 24, 2 × 12, 3 × 8, 4 × 6
" !
4 × 6
4 × 6
24
!
F 24 = 4 6 = 2 3
#$
n
!p×q(p ≤ q)
!
F n
F n = p q
1-1.
18
!! F 18
1-2.
48
!!F 48
1-3.
!F 221
1-4.
!F 2 99
1-5.
n
F n = 1
!
50%
%& %&'
"(
2
3
4
128
25 × 35
2
3
4
8
12
16
20
) *+
%&
,
500
!
2
1000
2
2 3 4 8 12 16 20
Þ
25 × 35 25 × 17 1 2 25 × 11 2 3 11 1 2 × 17 1 2
11 1 2 × 8 3 4 8 1 3 × 8 3 4
6 1 4 × 8 3 4 6 1 4 × 7
2-1. a) 64
%&32
%&b) 25
%&18
%&c)
! %&
d)
- -12 .5
.a) 64
"(%&24
"(%&b) 7
"(%&90
"(%&c) 96
"(%&DZ
25%
# # #
+ 1 2
3
4
* + 4$ +
π = 3.141592653 √
2 = 1.4142135
Ì
3-1.
+/3-2.
DZ44 +
+
1-1.
18
1 × 18, 2 × 9, 3 × 6
!
3 × 6
3 × 6
18
!F 18 = 3 6 = 1 2
1-2.
48
1 × 48, 2 × 24, 3 × 16, 4 × 12, 6 × 8
5 !
6 × 8
6 × 8
48
!F 48 = 6 8 = 3 4
1-3.
221 = 13 × 17
221
1 × 221, 13 × 17
!
13 × 17
13 × 17
221
!F 221 = 13 17
1-4.
2 99
1 × 2 99 , 2 1 × 2 98 , 2 2 × 2 97 , · · · 2 44 × 2 45
45
!2 44 ×2 45 2 44 ×2 45
2 99 ! F 2 99 = 2 2 44 45 = 1 2
1-5. p × q(p ≤ q) n F = 1
b) 25 = 5 × 5
%&25
5 × 35
5 = 5 × 7,
18 = 3 × 6
%&25
3 × 35
6 = 8 1
3 × 5 5 6 .
c)
p × q
n
!n
%&25
p × 35 q ,
25
p
q
q
d)
25 × 35
12 .5 = 70
--
70
e)
70 = 7 × 10
-25
7 × 35
10 = 3 4
7 × 3 1 2 .
f)
25
5 × 7
32
4 .375 × 6.25
5 > 4.375, 7 > 6.25
25
Æ!
32
g)
n = p × q
1 ≤ p ≤ q
pq ≤ 128
25 p × 35 q
1 .2 = 6 5 =
25 p 35 q
= 5 q
7 p
1 .2 = 6 5 =
35 q 25 p
= 7 p 5 q .
42 p = 25q
7 p = 6q
42 p = 25q
42 |q, 25|p
42 · · · 25|pq
pq ≤ 128
77 p = 6q
pq ≤ 128
p = 6, q = 7
6 × 7 = 42
2-2. a) 64 = 8 × 8
"(%&31
8 × 43
8 = 3 7
8 × 5 3 8 ; 24 = 4 × 6
"(%&31
4 × 43
6 = 7 3
4 × 7 1 6 . b) 7 = 1 × 7
"(%&31
1 × 43
7 = 31 × 6 1 7 ; 90 = 9 × 10
"(%&31
9 × 43
10 = 3 4
9 × 4 3 10 . c) 96 = 8 × 12
"(%&31
8 × 43
12 = 3 7
8 × 3 7 12 .
3-1.
!x
y
+2x y
+
x y
62 x y = y
x ⇒ y x
2
= 2 .
#+