中一數學喔~~~【20點】

2009-11-30 12:13 am

一元一次方程
1. 4(7-3b)=-5b
2. 7+8f=5f+34
要步驟喔~~~
謝謝各位的幫助=]]]]

回答 (4)

2009-11-30 1:25 am

✔ 最佳答案

1. 4(7-3b)=-5b
4x7+4x(-3b)=-5b
28-12b=-5b
-12b+5b=-28
7b=-28
b=-28/7
b = - 4

2. 7+8f=5f+34
8f-5f=34-7
3f=27
f =27/3
f = 9

👍 0 👎 0

2009-11-30 1:03 am

I think it's like this:

1. 4(7-3b)=-5b

28-12b=-5b

28=12b-5b

28=7b

4=b

2. 7+8f=5f+34

8f-5f=34-7

3f=27

f=9

I hope I can help you.

參考: Me

👍 0 👎 0

2009-11-30 12:20 am

1. 4(7-3b)=-5b
28-12b=-5b
28=7b
b=4

2. 7+8f=5f+34
8f-5f=34-7
3f=27
f=9

參考: me

👍 0 👎 0

2009-11-30 12:19 am

1. 4(7-3b)= -5b
28-12b= -5b
-12b+5b= -28
-7b= -28
b=4,,

2. 7+8f=5f+34
8f-5f=34-7
3f=27
f=9,, 不用客氣＾＾

👍 0 👎 0