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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
+
2
)
(
x
+
9
)
=
4
(
3
x
+
5
)
(2)
2
x
+
6
x
+
1
=
7
x
+
73
(3)
2
x
+
10
x
+
8
=
11
x
+
38
(4)
2
x
−
8
x
+
5
=
10
(
−
x
+
2
)
(5)
2
x
−
10
x
−
3
=
3
(
−8
x
−
17
)
©2026 数学クラブ http://sugaku.club/
月 日( )
【解答例】
(1)
(
x
+
2
)
(
x
+
9
)
=
4
(
3
x
+
5
)
2
x
+
11
x
+
18
=
12
x
+
20
2
x
−
x
−
2
=
0
(
x
+
1
)
(
x
−
2
)
=
0
x
=
−1
,
2
(2)
2
x
+
6
x
+
1
=
7
x
+
73
2
x
−
x
−
72
=
0
(
x
−
9
)
(
x
+
8
)
=
0
x
=
9
,
−8
(3)
2
x
+
10
x
+
8
=
11
x
+
38
2
x
−
x
−
30
=
0
(
x
−
6
)
(
x
+
5
)
=
0
x
=
6
,
−5
(4)
2
x
−
8
x
+
5
=
10
(
−
x
+
2
)
2
x
+
2
x
−
15
=
0
(
x
+
5
)
(
x
−
3
)
=
0
x
=
−5
,
3
(5)
2
x
−
10
x
−
3
=
3
(
−8
x
−
17
)
2
x
+
14
x
+
48
=
0
(
x
+
6
)
(
x
+
8
)
=
0
x
=
−6
,
−8