题目内容
![]() | 60%×![]() | ![]() |
![]() | ![]() | ![]() |
125%X-X=28 | (1+40%)X=98 | 1-20%X=![]() |
1+20%X=![]() | 60%X+25=40 | 1-25%X=![]() |
X-25%X=![]() | 2X+30%X=9.2 | 80%X+12=40 |
X-20%X=16 | X+30%X=65 | 1-![]() ![]() |
解:
(1)
-50%=0.125;
(2)60%×
=0.5;
(3)1-
=
;
(4)
÷5=
;
(5)
+
=1;
(6)
-
=
;
(7)125%X-X=28,
0.25X=28,
0.25X÷0.25=28÷0.25,
X=112;
(8)(1+40%)X=98,
1.4X=98,
1.4X÷1.4=98÷1.4,
X=70;
(9)1-20%X=
,
1-20%X+20%X=
+20%X,
+20%X=1,
+20%X-
=1-
,
20%X=0.75,
20%X÷20%=0.75÷20%,
X=3.75;
(10)1+20%X=
,
1+20%X-1=
-1,
20%X=-0.75,
20%X÷20%=-0.75÷20%,
X=-3.75;
(11)60%X+25=40,
60%X+25-25=40-25,
60%X=15,
60%X÷60%=15÷60%,
X=25;
(12)1-25%X=
,
1-25%X+25%X=
+25%X,
+25%X=1,
+25%X-
=1-
,
25%X=0.25,
25%X÷25%=0.25÷25%,
X=1;
(13)X-25%X=
,
0.75X=
,
0.75X÷0.75=
÷0.75,
X=1;
(14)2X+30%X=9.2,
2.3X=9.2,
2.3X÷2.3=9.2÷2.3,
X=4;
(15)80%X+12=40,
80%X+12-12=40-12,
80%X=28,
80%X÷80%=28÷80%,
X=35;
(16)X-20%X=16,
0.8X=16,
0.8X÷0.8=16÷0.8,
X=20;
(17)X+30%X=65,
1.3X=65,
1.3X÷1.3=65÷1.3,
X=50;
(18)1-
X=
,
1-
X+
X=
+
X,
+
X=1,
+
X-
=1-
,
X=
,
X÷
=
÷
,
X=
.
分析:(1)、(2)、(3)、(4)、(5)、(6)根据分数和百分数加减乘除的计算方法进行计算;
(7)、(8)、(9)、(10)、(11)、(12)、(13)、(14)、(15)、(16)、(17)、(18)根据等式的性质进行解方程.
点评:本题主要考查解方程,根据等式的性质进行解答.
(1)
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(2)60%×
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(3)1-
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(4)
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(5)
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(6)
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(7)125%X-X=28,
0.25X=28,
0.25X÷0.25=28÷0.25,
X=112;
(8)(1+40%)X=98,
1.4X=98,
1.4X÷1.4=98÷1.4,
X=70;
(9)1-20%X=

1-20%X+20%X=
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20%X=0.75,
20%X÷20%=0.75÷20%,
X=3.75;
(10)1+20%X=
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1+20%X-1=
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20%X=-0.75,
20%X÷20%=-0.75÷20%,
X=-3.75;
(11)60%X+25=40,
60%X+25-25=40-25,
60%X=15,
60%X÷60%=15÷60%,
X=25;
(12)1-25%X=

1-25%X+25%X=
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25%X=0.25,
25%X÷25%=0.25÷25%,
X=1;
(13)X-25%X=
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0.75X=
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0.75X÷0.75=
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X=1;
(14)2X+30%X=9.2,
2.3X=9.2,
2.3X÷2.3=9.2÷2.3,
X=4;
(15)80%X+12=40,
80%X+12-12=40-12,
80%X=28,
80%X÷80%=28÷80%,
X=35;
(16)X-20%X=16,
0.8X=16,
0.8X÷0.8=16÷0.8,
X=20;
(17)X+30%X=65,
1.3X=65,
1.3X÷1.3=65÷1.3,
X=50;
(18)1-
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1-
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X=
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分析:(1)、(2)、(3)、(4)、(5)、(6)根据分数和百分数加减乘除的计算方法进行计算;
(7)、(8)、(9)、(10)、(11)、(12)、(13)、(14)、(15)、(16)、(17)、(18)根据等式的性质进行解方程.
点评:本题主要考查解方程,根据等式的性质进行解答.

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