Can someone show me a step by step process of how to solve these?

2016-03-28 9:06 pm
1. (1/6)^(-2x)=36

2. 10^(8x)-1=74

回答 (4)

2016-03-28 9:20 pm
1.
(1/6)^(-2x) = 36
[6^(-1)]^(-2x) = 6^2
6^(2x) = 6^2
2x = 2
x = 1


2.
10^(8x) - 1 = 74
10^(8x) = 75
8x = log75
x = (log75)/8
2016-03-28 9:10 pm
(1/6)^(- 2x) = 6^(2x) = 36

by observation, x = 1

10^(8x) - 1 = 74

10^(8x) = 75

(8x) log 10 = log 75
8x = log 75 ≈ 1.8506
x ≈ 0.2344
2016-03-28 9:33 pm
1. (1/6)^(-2x)=36=>
[6^(2x)]=6^2=>
2x=2=>
x=1

2. 10^(8x)-1=74=>
10^(8x)=75=>
8x=log(10)[75]=>
x=log(10)[75]/8=>
x=0.23438265...
2016-03-28 9:40 pm
1.
(1/6)^(-2x)=36
((1/6)^(-2))^x = 36
36^x = 36
x = (ln(36) + 2*i*pi*n) / ln(36), for any integer n
x = 1 + ((2*i*pi*n)/ln(36)), for any integer n
x =~ 1 + 1.7533562442637949741190966580666*i*n, for any integer n
If x is a real number, then n = 0, so x = 1

2.
10^(8x) - 1 = 74
(10^8)^x = 74 + 1
100000000^x = 75
x = (ln(75) + 2*i*pi*n) / ln(100000000), for any integer n
x =~ 0.2343826579239625058584437642 + 0.3410940884604603368714459063*i*n, for any integer n
If x is a real number, then n = 0, so x = log[100000000](75) =~ 0.2343826579239625058584437642


收錄日期: 2021-04-20 16:18:25
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