题目内容
22
|
x+1
|
x-5.375=1
|
x-(1
| ||||||||||||||
10
|
5-3.125+4
|
1
|
10.75-(5
|
分析:本题含有未知数的方程根据等式性质进行解答即可;
22
-(7.875-2
)+2
、可先根据减法的性质将括号去掉后,再根据加法交换律及结合律先将整数部分相加减,再将分数部分相加减;
其余算式根据四则混合运算的运算顺序进行计算:先算乘除,再算加减,有括号的要先算括号里面的.
22
| 5 |
| 6 |
| 11 |
| 12 |
| 5 |
| 24 |
其余算式根据四则混合运算的运算顺序进行计算:先算乘除,再算加减,有括号的要先算括号里面的.
解答:解:22
-(7.875-2
)+2
=22
-7
+2
+2
,
=(22-7+2+2)+(
+
+
-
),
=19+(
+
+
-
),
=19+1
,
=20
;
x+1
=3.85
x+1.25=3.85,
x=3.85-1.25
x=2.6;
x-5.375=1
x-5
=1
,
x=
+
,
x=
+
,
x=6
;
x-(1
-
)=2.125
x-(
-
)=2
,
x-
=2
,
x=3;
10
-x=5
x=10
-5
,
x=
-
,
x=
;
5-3.125+4
=5-3.125+4.75,
=1.875+4.75,
=6.625;
1
+2-3
=(1+2-3)+(
-
),
=0+
,
=
;
10.75-(5
+4.2-4
)
=10
-(5
+4
-4
)
=10
-(10-4
),
=10
-5
,
=
-
=5
.
| 5 |
| 6 |
| 11 |
| 12 |
| 5 |
| 24 |
=22
| 5 |
| 6 |
| 7 |
| 8 |
| 11 |
| 12 |
| 5 |
| 24 |
=(22-7+2+2)+(
| 5 |
| 6 |
| 11 |
| 12 |
| 5 |
| 24 |
| 7 |
| 8 |
=19+(
| 20 |
| 24 |
| 22 |
| 24 |
| 5 |
| 24 |
| 21 |
| 24 |
=19+1
| 1 |
| 12 |
=20
| 1 |
| 12 |
x+1
| 1 |
| 4 |
x+1.25=3.85,
x=3.85-1.25
x=2.6;
x-5.375=1
| 1 |
| 6 |
x-5
| 3 |
| 8 |
| 1 |
| 6 |
x=
| 7 |
| 6 |
| 43 |
| 8 |
x=
| 28 |
| 24 |
| 129 |
| 24 |
x=6
| 13 |
| 24 |
x-(1
| 1 |
| 4 |
| 3 |
| 8 |
x-(
| 10 |
| 8 |
| 3 |
| 8 |
| 1 |
| 8 |
x-
| 7 |
| 8 |
| 1 |
| 8 |
x=3;
10
| 1 |
| 4 |
| 7 |
| 12 |
x=10
| 1 |
| 4 |
| 7 |
| 12 |
x=
| 123 |
| 12 |
| 67 |
| 12 |
x=
| 14 |
| 3 |
5-3.125+4
| 3 |
| 4 |
=5-3.125+4.75,
=1.875+4.75,
=6.625;
1
| 3 |
| 4 |
| 1 |
| 2 |
=(1+2-3)+(
| 3 |
| 4 |
| 2 |
| 4 |
=0+
| 1 |
| 4 |
=
| 1 |
| 4 |
10.75-(5
| 4 |
| 5 |
| 2 |
| 3 |
=10
| 3 |
| 4 |
| 4 |
| 5 |
| 1 |
| 5 |
| 2 |
| 3 |
=10
| 3 |
| 4 |
| 2 |
| 3 |
=10
| 3 |
| 4 |
| 1 |
| 3 |
=
| 129 |
| 12 |
| 64 |
| 12 |
=5
| 5 |
| 12 |
点评:当算式中同时含有分数与小数时,要根据式中数据的特点灵活将式中的小数与分数进行互化,然后再进行计算.
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