請計算以下題目,要有步驟
3^(x+1)+3^(x)-36=0
5^(x+1)-5x-100=0
9^(x)+9^(x-1)-10=0
解指數定律方程一問
2009-10-29 5:14 am
回答 (2)
2009-10-29 5:25 am
✔ 最佳答案
3^(x+1)+3^(x)-36=03(3^x) + 3^x = 36
(3+1)(3^x) = 36
3^x = 9
3^x = 3^2
x = 2
5^(x+1)-5x-100=0
5(5^x) - 5^x = 100
(5-1)(5^x) = 100
5^x = 25
5^x = 5^2
x = 2
9^(x)+9^(x-1)-10=0
9[9^(x-1)] + 9^(x-1) = 10
(9+1)(9^(x-1)) = 10
9^(x-1) = 1
9^(x-1) = 9^0
x-1 = 0
x = 1
2009-10-31 3:06 am
3^(x+1)+3^(x)-36=0
3(3^x) + 3^x = 36
(3+1)(3^x) = 36
3^x = 9
3^x = 3^2
x = 2
5^(x+1)-5x-100=0
5(5^x) - 5^x = 100
(5-1)(5^x) = 100
5^x = 25
5^x = 5^2
x = 2
9^(x)+9^(x-1)-10=0
9[9^(x-1)] + 9^(x-1) = 10
(9+1)(9^(x-1)) = 10
9^(x-1) = 1
9^(x-1) = 9^0
x-1 = 0
x = 1
3(3^x) + 3^x = 36
(3+1)(3^x) = 36
3^x = 9
3^x = 3^2
x = 2
5^(x+1)-5x-100=0
5(5^x) - 5^x = 100
(5-1)(5^x) = 100
5^x = 25
5^x = 5^2
x = 2
9^(x)+9^(x-1)-10=0
9[9^(x-1)] + 9^(x-1) = 10
(9+1)(9^(x-1)) = 10
9^(x-1) = 1
9^(x-1) = 9^0
x-1 = 0
x = 1
參考: me^^
收錄日期: 2021-04-21 22:06:01
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20091028000051KK01308