a+b=c
a+c=4b
2b+c=?c
數學,a+b=c , a+c=4b , 2b+c=?c
2012-07-31 2:03 am
回答 (3)
2012-07-31 2:30 am
✔ 最佳答案
a+b=c a+c=4b
2b+c=?c
a+b+a+b+a+c=4b+c+c
3a+2b+c =4b+2c
3a+2b-4b =2c-c
3a-2b =c
3a = c+2b
2b+c =3a
a+b=c
a =c-b
a =-b+c
a =-(-b+c)
a =b-c
3a =3b-c
2b+c+3a =3a+3b-c
2b+c= 3b-c
2012-07-31 6:05 am
a+b=c
a=c-b
--------------
代入2式:
c-b+c=4b
2c=5b
2c*2/5=5b*2/5
4c/5=2b
-------------------
代入3式
4c/5 +c
=(9/5) c
a=c-b
--------------
代入2式:
c-b+c=4b
2c=5b
2c*2/5=5b*2/5
4c/5=2b
-------------------
代入3式
4c/5 +c
=(9/5) c
2012-07-31 3:15 am
a+b=c
a+c=4b
2b+c=?c
Sol
a+b=c
a+c=4b
(a+b)－(a+c)=c－4b
b－c=c－4b
5b=2c
b=(2c)/5
2b+c=(4/5)c+c=(9/5)c
a+c=4b
2b+c=?c
Sol
a+b=c
a+c=4b
(a+b)－(a+c)=c－4b
b－c=c－4b
5b=2c
b=(2c)/5
2b+c=(4/5)c+c=(9/5)c
收錄日期: 2021-04-13 18:52:45
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20120730000051KK00639