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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
+
5
)
(
x
+
8
)
=
2
(
x
+
5
)
(2)
2
x
+
9
x
+
7
=
−4
x
−
29
(3)
2
x
+
4
x
−
3
=
29
(4)
2
x
−
7
x
−
2
=
−17
x
−
26
(5)
(
x
−
1
)
(
x
−
2
)
=
11
(
−
x
+
1
)
©2026 数学クラブ http://sugaku.club/
月 日( )
【解答例】
(1)
(
x
+
5
)
(
x
+
8
)
=
2
(
x
+
5
)
2
x
+
13
x
+
40
=
2
x
+
10
2
x
+
11
x
+
30
=
0
(
x
+
6
)
(
x
+
5
)
=
0
x
=
−6
,
−5
(2)
2
x
+
9
x
+
7
=
−4
x
−
29
2
x
+
13
x
+
36
=
0
(
x
+
4
)
(
x
+
9
)
=
0
x
=
−4
,
−9
(3)
2
x
+
4
x
−
3
=
29
2
x
+
4
x
−
32
=
0
(
x
+
8
)
(
x
−
4
)
=
0
x
=
−8
,
4
(4)
2
x
−
7
x
−
2
=
−17
x
−
26
2
x
+
10
x
+
24
=
0
(
x
+
4
)
(
x
+
6
)
=
0
x
=
−4
,
−6
(5)
(
x
−
1
)
(
x
−
2
)
=
11
(
−
x
+
1
)
2
x
−
3
x
+
2
=
−11
x
+
11
2
x
+
8
x
−
9
=
0
(
x
−
1
)
(
x
+
9
)
=
0
x
=
1
,
−9