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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)
2
x
+
8
x
+
9
=
7
x
+
29
(2)
2
x
+
2
x
+
10
=
2
(
4
x
+
25
)
(3)
(
x
−
1
)
(
x
+
6
)
=
2
(
7
x
−
10
)
(4)
(
x
+
9
)
(
x
−
6
)
=
3
(
x
+
9
)
(5)
2
x
+
10
x
+
4
=
4
x
+
11
©2026 数学クラブ http://sugaku.club/
月 日( )
【解答例】
(1)
2
x
+
8
x
+
9
=
7
x
+
29
2
x
+
x
−
20
=
0
(
x
+
5
)
(
x
−
4
)
=
0
x
=
−5
,
4
(2)
2
x
+
2
x
+
10
=
2
(
4
x
+
25
)
2
x
−
6
x
−
40
=
0
(
x
−
10
)
(
x
+
4
)
=
0
x
=
10
,
−4
(3)
(
x
−
1
)
(
x
+
6
)
=
2
(
7
x
−
10
)
2
x
+
5
x
−
6
=
14
x
−
20
2
x
−
9
x
+
14
=
0
(
x
−
2
)
(
x
−
7
)
=
0
x
=
2
,
7
(4)
(
x
+
9
)
(
x
−
6
)
=
3
(
x
+
9
)
2
x
+
3
x
−
54
=
3
x
+
27
2
x
−
81
=
0
(
x
+
9
)
(
x
−
9
)
=
0
x
=
−9
,
9
(5)
2
x
+
10
x
+
4
=
4
x
+
11
2
x
+
6
x
−
7
=
0
(
x
+
7
)
(
x
−
1
)
=
0
x
=
−7
,
1