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©2025 数学クラブ http://sugaku.club/
月 日( )
● 次の比例式を解きなさい
[0G1-00]
(1)
−20
:
5
x
=
−16
:
−12
(2)
25
:
x
−
1
=
5
:
−3
(3)
−4
x
:
−8
=
−1
:
−2
(4)
−2
:
−6
=
−2
x
:
−30
(5)
−12
:
−4
=
−6
:
x
+
2
(6)
x
−
2
:
−20
=
−4
:
20
(7)
2
x
:
40
=
−4
:
16
(8)
3
:
15
=
−3
x
:
75
(9)
−2
x
:
8
=
8
:
−2
(10)
−2
:
1
=
−16
:
4
x
(11)
2
x
:
8
=
−12
:
−16
(12)
9
:
−3
x
=
−15
:
−25
(13)
x
+
3
:
−4
=
25
:
20
(14)
−3
:
x
−
4
=
4
:
−16
(15)
−8
:
2
=
−100
:
5
x
(16)
x
+
5
:
1
=
3
:
−1
©2025 数学クラブ http://sugaku.club/
月 日( )
【解答例】
(1)
−20
:
5
x
=
−16
:
−12
−16
×
5
x
=
−20
×
(
−12
)
x
=
−3
(2)
25
:
x
−
1
=
5
:
−3
5
×
(
x
−
1
)
=
25
×
(
−3
)
x
−
1
=
−15
x
=
−14
(3)
−4
x
:
−8
=
−1
:
−2
−2
×
(
−4
)
x
=
−8
×
(
−1
)
x
=
1
(4)
−2
:
−6
=
−2
x
:
−30
−6
×
(
−2
)
x
=
−2
×
(
−30
)
x
=
5
(5)
−12
:
−4
=
−6
:
x
+
2
−12
×
(
x
+
2
)
=
−4
×
(
−6
)
x
+
2
=
−2
x
=
−4
(6)
x
−
2
:
−20
=
−4
:
20
20
×
(
x
−
2
)
=
−20
×
(
−4
)
x
−
2
=
4
x
=
6
(7)
2
x
:
40
=
−4
:
16
16
×
2
x
=
40
×
(
−4
)
x
=
−5
(8)
3
:
15
=
−3
x
:
75
15
×
(
−3
)
x
=
3
×
75
x
=
−5
(9)
−2
x
:
8
=
8
:
−2
−2
×
(
−2
)
x
=
8
×
8
x
=
16
(10)
−2
:
1
=
−16
:
4
x
−2
×
4
x
=
−16
x
=
2
(11)
2
x
:
8
=
−12
:
−16
−16
×
2
x
=
8
×
(
−12
)
x
=
3
(12)
9
:
−3
x
=
−15
:
−25
−15
×
(
−3
)
x
=
9
×
(
−25
)
x
=
−5
(13)
x
+
3
:
−4
=
25
:
20
20
×
(
x
+
3
)
=
−4
×
25
x
+
3
=
−5
x
=
−8
(14)
−3
:
x
−
4
=
4
:
−16
4
×
(
x
−
4
)
=
−3
×
(
−16
)
x
−
4
=
12
x
=
16
(15)
−8
:
2
=
−100
:
5
x
−8
×
5
x
=
2
×
(
−100
)
x
=
5
(16)
x
+
5
:
1
=
3
:
−1
−
(
x
+
5
)
=
3
x
+
5
=
−3
x
=
−8