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©2026 数学クラブ http://sugaku.club/
月 日( )
● 次の方程式を解きなさい
[225-00]
(1)
(
x
+
4
)
(
x
+
9
)
=
6
(
2
x
+
13
)
(2)
(
x
+
8
)
(
x
+
9
)
=
2
(
5
x
+
31
)
(3)
2
x
−
6
x
−
3
=
4
(
−4
x
−
7
)
(4)
(
x
−
4
)
(
x
+
8
)
=
−9
x
−
74
(5)
2
x
+
10
x
−
8
=
2
(
3
x
+
2
)
©2026 数学クラブ http://sugaku.club/
月 日( )
【解答例】
(1)
(
x
+
4
)
(
x
+
9
)
=
6
(
2
x
+
13
)
2
x
+
13
x
+
36
=
12
x
+
78
2
x
+
x
−
42
=
0
(
x
+
7
)
(
x
−
6
)
=
0
x
=
−7
,
6
(2)
(
x
+
8
)
(
x
+
9
)
=
2
(
5
x
+
31
)
2
x
+
17
x
+
72
=
10
x
+
62
2
x
+
7
x
+
10
=
0
(
x
+
2
)
(
x
+
5
)
=
0
x
=
−2
,
−5
(3)
2
x
−
6
x
−
3
=
4
(
−4
x
−
7
)
2
x
+
10
x
+
25
=
0
2
(
x
+
5
)
=
0
x
=
−5
(4)
(
x
−
4
)
(
x
+
8
)
=
−9
x
−
74
2
x
+
4
x
−
32
=
−9
x
−
74
2
x
+
13
x
+
42
=
0
(
x
+
7
)
(
x
+
6
)
=
0
x
=
−7
,
−6
(5)
2
x
+
10
x
−
8
=
2
(
3
x
+
2
)
2
x
+
4
x
−
12
=
0
(
x
−
2
)
(
x
+
6
)
=
0
x
=
2
,
−6