题目内容
解比例
0.6:4.8=12:X |
|
45:X=18:26 | ||||||||||||
9:0.09=X:0.15 | x:
|
(3.8-x):7=2:7 | ||||||||||||
|
x:
|
| ||||||||||||
0.375:X=
|
X:5=
|
| ||||||||||||
|
0.45:X=
|
1.25:0.25=X:1.6 | ||||||||||||
X:48=3:1.2 |
|
| ||||||||||||
12:5=3.6:X | X:0.25=4:3 | 1.5:X=3.6:4.8 | ||||||||||||
6.5:X=3
|
0.6:1
|
1.5:
| ||||||||||||
0.75:X=1
|
3.6:X=0.48:
|
1.25:0.2=X:1
|
分析:先根据比例基本性质,两内项之积等于两外项之积,化简方程,再依据等式的性质,求解.
解答:解:(1)0.6:4.8=12:X,
0.6X=4.8×12,
0.6X÷0.6=57.6÷0.6,
X=96;
(2)
:
=1.2:X,
X=
×1.2,
X÷
=0.3÷
,
X=0.45;
(3)45:X=18:26,
18X=45×26,
18X÷18=1170÷18,
X=65;
(4)9:0.09=X:0.15,
0.09X=0.15×9,
0.09X÷0.09=1.35÷0.09,
X=15;
(5)x:
=
:
,
x:=
×
,
x÷
=
÷
,
x=
;
(6)(3.8-x):7=2:7,
(3.8-x)×7=2×7,
(3.8-x)×7÷7=14÷7,
3.8-x=2,
3.8-x+x=2+x,
3.8=2+x,
3.8-2=2+x-2,
x=1.8;
(7)
=
,
7X=0.8×5,
7X÷7=4÷7,
X=
;
(8)x:
=0.3:
,
x=
×0.3,
x÷
=
÷
,
x=
;
(9)
=
,
6X=1.6×2.4,
6X÷6=3.84÷6,
X=0.64;
(10)0.375:X=
:60%,
X=0.375×60%,
X÷
=
÷
,
X=
;
(11)X:5=
:
,
X=5×
,
X÷
=3÷
,
X=6;
(12)
=
,
0.4x=1.4×15,
0.4x÷0.4=21÷0.4,
x=52.5;
(13)
:X=0.25:6,
0.25X=
×6,
0.25X÷0.25=2.4÷0.25,
X=9.6;
(14)0.45:X=
:20,
X=0.45×20,
X÷
=9÷
,
X=31.5;
(15)1.25:0.25=X:1.6,
0.25X=1.25×1.6,
0.25X÷0.25=2÷0.25,
X=8;
(16)X:48=3:1.2,
1.2X=48×3,
1.2X÷1.2=144÷1.2,
X=120;
(17)
:X=1:0.25,
X=0.25×
,
X=
;
(18)
=
,
2.5X=1.6×5,
2.5X÷2.5=8÷2.5,
X=3.2;
(19)12:5=3.6:X,
12X=5×3.6,
12X÷12=18÷12,
X=1.5;
(20)X:0.25=4:3,
3X=0.25×4,
3X÷3=1÷3,
X=
;
(21)1.5:X=3.6:4.8,
3.6X=1.5×4.8,
3.6X÷3.6=7.2÷3.6,
X=2;
(22)6.5:X=3
:4,
3
X=4×6.5,
3
X÷3
=26÷3
,
X=8;
(23)0.6:1
=
:X,
0.6X=1
×
,
0.6X÷0.6=
÷0.6,
X=
;
(24)1.5:
=0.36:X,
1.5X=
×0.36,
1.5X÷1.5=0.27÷1.5,
X=0.18;
(25)0.75:X=1
:2,
1
X=2×0.75,
1
X÷1
=1.5÷1
,
X=1.2;
(26)3.6:X=0.48:
,
0.48X=3.6×
,
0.48X÷0.48=0.432÷0.48,
X=0.9;
(27)1.25:0.2=X:1
,
0.2X=1.25×1
,
0.2X÷0.2=2÷0.2,
X=10;
0.6X=4.8×12,
0.6X÷0.6=57.6÷0.6,
X=96;
(2)
2 |
3 |
1 |
4 |
2 |
3 |
1 |
4 |
2 |
3 |
2 |
3 |
2 |
3 |
X=0.45;
(3)45:X=18:26,
18X=45×26,
18X÷18=1170÷18,
X=65;
(4)9:0.09=X:0.15,
0.09X=0.15×9,
0.09X÷0.09=1.35÷0.09,
X=15;
(5)x:
1 |
20 |
3 |
4 |
1 |
5 |
1 |
5 |
1 |
20 |
3 |
4 |
1 |
5 |
1 |
5 |
3 |
80 |
1 |
5 |
x=
3 |
16 |
(6)(3.8-x):7=2:7,
(3.8-x)×7=2×7,
(3.8-x)×7÷7=14÷7,
3.8-x=2,
3.8-x+x=2+x,
3.8=2+x,
3.8-2=2+x-2,
x=1.8;
(7)
0.8 |
X |
7 |
5 |
7X=0.8×5,
7X÷7=4÷7,
X=
4 |
7 |
(8)x:
5 |
7 |
5 |
14 |
5 |
14 |
5 |
7 |
5 |
14 |
5 |
14 |
3 |
14 |
5 |
14 |
x=
3 |
5 |
(9)
1.6 |
6 |
X |
2.4 |
6X=1.6×2.4,
6X÷6=3.84÷6,
X=0.64;
(10)0.375:X=
1 |
20 |
1 |
20 |
1 |
20 |
1 |
20 |
9 |
40 |
1 |
20 |
X=
9 |
2 |
(11)X:5=
18 |
30 |
1 |
2 |
1 |
2 |
18 |
30 |
1 |
2 |
1 |
2 |
1 |
2 |
X=6;
(12)
1.4 |
x |
0.4 |
15 |
0.4x=1.4×15,
0.4x÷0.4=21÷0.4,
x=52.5;
(13)
2 |
5 |
0.25X=
2 |
5 |
0.25X÷0.25=2.4÷0.25,
X=9.6;
(14)0.45:X=
2 |
7 |
2 |
7 |
2 |
7 |
2 |
7 |
2 |
7 |
X=31.5;
(15)1.25:0.25=X:1.6,
0.25X=1.25×1.6,
0.25X÷0.25=2÷0.25,
X=8;
(16)X:48=3:1.2,
1.2X=48×3,
1.2X÷1.2=144÷1.2,
X=120;
(17)
7 |
8 |
X=0.25×
7 |
8 |
X=
7 |
32 |
(18)
1.6 |
X |
2.5 |
5 |
2.5X=1.6×5,
2.5X÷2.5=8÷2.5,
X=3.2;
(19)12:5=3.6:X,
12X=5×3.6,
12X÷12=18÷12,
X=1.5;
(20)X:0.25=4:3,
3X=0.25×4,
3X÷3=1÷3,
X=
1 |
3 |
(21)1.5:X=3.6:4.8,
3.6X=1.5×4.8,
3.6X÷3.6=7.2÷3.6,
X=2;
(22)6.5:X=3
1 |
4 |
3
1 |
4 |
3
1 |
4 |
1 |
4 |
1 |
4 |
X=8;
(23)0.6:1
1 |
5 |
4 |
5 |
0.6X=1
1 |
5 |
4 |
5 |
0.6X÷0.6=
24 |
25 |
X=
8 |
5 |
(24)1.5:
3 |
4 |
1.5X=
3 |
4 |
1.5X÷1.5=0.27÷1.5,
X=0.18;
(25)0.75:X=1
1 |
4 |
1
1 |
4 |
1
1 |
4 |
1 |
4 |
1 |
4 |
X=1.2;
(26)3.6:X=0.48:
3 |
25 |
0.48X=3.6×
3 |
25 |
0.48X÷0.48=0.432÷0.48,
X=0.9;
(27)1.25:0.2=X:1
3 |
5 |
0.2X=1.25×1
3 |
5 |
0.2X÷0.2=2÷0.2,
X=10;
点评:本题主要考查学生运用等式的性质,以及比例基本性质解方程的能力,注意等号对齐.
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