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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
[211-00]
(1)
2
(
x
−
1
)
=
8
(2)
2
(
x
＋
9
)
=
25
(3)
2
(
x
−
1
)
−
4
=
0
(4)
2
(
x
−
4
)
=
6
(5)
2
(
x
＋
1
)
=
81
(6)
2
(
x
−
1
)
=
5
(7)
2
(
x
＋
9
)
−
9
=
0
(8)
2
(
x
＋
4
)
=
1
(9)
2
(
x
＋
5
)
−
3
=
0
(10)
2
(
x
＋
5
)
=
5
(11)
2
(
x
−
1
)
=
9
(12)
2
(
x
−
5
)
−
49
=
0
©2026 数学クラブ http://sugaku.club/
月 日（ ）
【解答例】
(1)
2
(
x
−
1
)
=
8
x
−
1
2
=
±
2
x
2
=
1
±
2
(2)
2
(
x
＋
9
)
=
25
x
＋
9
=
±
5
x
=
−
9
±
5
x
=
−4
，
−14
(3)
2
(
x
−
1
)
−
4
=
0
x
−
1
=
±
2
x
=
1
±
2
x
=
3
，
−1
(4)
2
(
x
−
4
)
=
6
x
−
4
6
=
±
x
6
=
4
±
(5)
2
(
x
＋
1
)
=
81
x
＋
1
=
±
9
x
=
−
1
±
9
x
=
8
，
−10
(6)
2
(
x
−
1
)
=
5
x
−
1
5
=
±
x
5
=
1
±
(7)
2
(
x
＋
9
)
−
9
=
0
x
＋
9
=
±
3
x
=
−
9
±
3
x
=
−6
，
−12
(8)
2
(
x
＋
4
)
=
1
x
＋
4
=
±
1
x
=
−
4
±
1
x
=
−3
，
−5
(9)
2
(
x
＋
5
)
−
3
=
0
x
＋
5
3
=
±
x
3
=
−
5
±
(10)
2
(
x
＋
5
)
=
5
x
＋
5
5
=
±
x
5
=
−
5
±
(11)
2
(
x
−
1
)
=
9
x
−
1
=
±
3
x
=
1
±
3
x
=
4
，
−2
(12)
2
(
x
−
5
)
−
49
=
0
x
−
5
=
±
7
x
=
5
±
7
x
=
12
，
−2