解二元一次聯立方程式?
回答 (2)
2016-03-17 4:06 am
3^x+5^y=134 i
3^(x+1)+5^(y-1)=52 ii
由ii
3(3^x)+0.2(5^y)=52
15(3^x)+(5^y)=260 iii
iii-i
14(3^x)=126
3^x=9
x=2
代x=2入i
3^2+(5^y)=134
5^y=125
y=3
x-y=2-3=-1
3^(x+1)+5^(y-1)=52 ii
由ii
3(3^x)+0.2(5^y)=52
15(3^x)+(5^y)=260 iii
iii-i
14(3^x)=126
3^x=9
x=2
代x=2入i
3^2+(5^y)=134
5^y=125
y=3
x-y=2-3=-1
收錄日期: 2021-04-18 14:29:32
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20160220095556AAUQUsX