中一數學題~超急!!!!!!!!!!!!!!!!!(15點)

2010-09-02 1:01 am
代數
1) 3a+27=4a+6 a=?

2) 5a-4=17-2a a=?

負數代數

1) 12+3a= -4 - 5a

回答 (7)

2010-09-02 1:05 am
✔ 最佳答案
3a+27=4a+6
+27-6=a
a=21

5a-4=17-2a
7a=21
a=3

12+3a=-4-5a
-8a=16
a=-2

2010-09-01 17:07:28 補充:
其實個數搬去第二邊就係+變-,-變+
如果係12代表+12,去第二邊變-12
2010-09-05 10:18 pm
代數
1) 解: 3a+27=4a+6
4a-3a=27-6
a=21

2) 解: 5a-4=17-2a
5a=17-2a+4
5a=21-2a
2a+5a=21
7a=21
a=3

負數代數
1) 解: 12+3a=-4-5a
12+3a+5a=-4
12+8a=-4
8a=-4-12
8a=-16
a=-2

2010-09-05 14:25:49 補充:
1) 3x21+27=4x21+6
63+27=84+6
90=90

2) 5x3-4=17-2x3
15-4=17-6
11=11

1) 12+3x(-2)=-4-5x(-2)
12+(-6)=-4-(-10)
12-6=-4+10
6=6
參考: me, me
2010-09-03 2:48 am
3a+27=4a+6a
3a+27=10a
3a-10a=-27
-7a=-27
a=七分之二十七
5a-4=17-2a
5a+2a=17+4
7a=21
a=3
12+3a= -4-5a
3a+5a= -4-12
8a= -16
a= -2

2010-09-02 18:50:52 補充:
corr:
1)3a+27=4a+6
+27-6=a
a=21
2010-09-02 1:57 am
3a+27=4a+6
27-6=4a-3a
21=a
a=21

5a-4=17-2a
5a+2a=17+4
7a=21
a=21/7
a=3

12+3a=-4-5a
3a-5a=-4-12
-2a=-16
a=-16/-2
a=8
參考: me
2010-09-02 1:12 am
1) 3a+27=4a+6
27-6=4a-3a
21= a

2) 5a-4=17-2a
5a+2a=17+4
7a=21
a=3

負數代數

1)12+3a= -4 - 5a
3a+5a=-4-12
8a= -16
a= -2
2010-09-02 1:10 am
1)3a+27=4a+6a
27 =4a+6a-3a
27=7a
a=27/7 (27除以7)
2) 5a-4=17-2a
5a-4+2a=17
7a-4=17
7a=21
a=3

負數代數

1) 12+3a= -4 - 5a
12+3a+5a=-4
12+8a=-4
8a=-4-12
8a=-16
a=-2
2010-09-02 1:08 am
1) 3a+27=4a+6
27-6=4a-3a
21= a

2) 5a-4=17-2a
5a+2a=17+4
7a=21
a=3

負數代數

1) 12+3a= -4 - 5a
3a+5a=-4-12
8a= -16
a= -2
參考: me


收錄日期: 2021-04-13 17:29:03
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