1
?2
?3
?
?“”“”
?
1
1
215?
31553
15=5×3
3515?
2
115
215=3×43
154333(:)
3
1
2
3
1
44
5123
3
115
7
15721
“=”
215
315
:
415
357
4
,
1
15 = 5 × 3
15 = 3 × 4 3
15 = 7 × 2 1
15 = 3 × 5
15 = 2 × 6 3
15 = 1 × 8 7
1
2,,
2
(1)5
2
6()
3
4
,
521=4×4+5
?
1?
17=□×5+
17=□×4+
:
2
317,,
17=□× +
()
4
26
5 3
12 7
:26=( )× +
15 = 5 × 3
15 = 3 × 4 3
15 = 7 × 2 1
15 = 3 × 5
15 = 2 × 6 3
15 = 1 × 8 7
p38~39