[文字サイズの変更]
▼
▲
©2026 数学クラブ http://sugaku.club/
月 日( )
● 次の比例式を解きなさい
[0G1-00]
(1)
2
:
4
=
−
x
:
−2
(2)
−20
:
−12
=
−25
:
−5
x
(3)
−3
:
x
+
4
=
−12
:
−20
(4)
−1
:
−4
=
4
x
:
48
(5)
4
:
4
x
=
−1
:
−2
(6)
5
:
x
+
4
=
3
:
6
(7)
3
:
4
=
18
:
2
x
(8)
9
:
−3
=
−24
:
4
x
(9)
−3
:
−9
=
−5
:
−5
x
(10)
−15
:
3
=
x
−
5
:
−1
(11)
−8
:
−
x
=
10
:
−5
(12)
3
x
:
−18
=
3
:
2
(13)
−8
:
4
x
=
−6
:
3
(14)
3
:
−4
=
−
x
:
−8
(15)
−5
:
−4
=
−15
:
x
+
3
(16)
−4
:
1
=
−24
:
3
x
©2026 数学クラブ http://sugaku.club/
月 日( )
【解答例】
(1)
2
:
4
=
−
x
:
−2
4
×
(
−1
)
x
=
2
×
(
−2
)
x
=
1
(2)
−20
:
−12
=
−25
:
−5
x
−20
×
(
−5
)
x
=
−12
×
(
−25
)
x
=
3
(3)
−3
:
x
+
4
=
−12
:
−20
−12
×
(
x
+
4
)
=
−3
×
(
−20
)
x
+
4
=
−5
x
=
−9
(4)
−1
:
−4
=
4
x
:
48
−4
×
4
x
=
−
48
x
=
3
(5)
4
:
4
x
=
−1
:
−2
−
4
x
=
4
×
(
−2
)
x
=
2
(6)
5
:
x
+
4
=
3
:
6
3
×
(
x
+
4
)
=
5
×
6
x
+
4
=
10
x
=
6
(7)
3
:
4
=
18
:
2
x
3
×
2
x
=
4
×
18
x
=
12
(8)
9
:
−3
=
−24
:
4
x
9
×
4
x
=
−3
×
(
−24
)
x
=
2
(9)
−3
:
−9
=
−5
:
−5
x
−3
×
(
−5
)
x
=
−9
×
(
−5
)
x
=
3
(10)
−15
:
3
=
x
−
5
:
−1
3
×
(
x
−
5
)
=
−15
×
(
−1
)
x
−
5
=
5
x
=
10
(11)
−8
:
−
x
=
10
:
−5
10
×
(
−1
)
x
=
−8
×
(
−5
)
x
=
−4
(12)
3
x
:
−18
=
3
:
2
2
×
3
x
=
−18
×
3
x
=
−9
(13)
−8
:
4
x
=
−6
:
3
−6
×
4
x
=
−8
×
3
x
=
1
(14)
3
:
−4
=
−
x
:
−8
−4
×
(
−1
)
x
=
3
×
(
−8
)
x
=
−6
(15)
−5
:
−4
=
−15
:
x
+
3
−5
×
(
x
+
3
)
=
−4
×
(
−15
)
x
+
3
=
−12
x
=
−15
(16)
−4
:
1
=
−24
:
3
x
−4
×
3
x
=
−24
x
=
2