Simplifying the Expression: ((1)/(49))^(1+log 7 2)+5^(-log(15)7)
This article will guide you through simplifying the given expression: ((1)/(49))^(1+log 7 2)+5^(-log(15)7). We'll utilize key properties of logarithms and exponents to achieve a simplified form.
Breaking Down the Expression
Let's start by dissecting the expression into manageable parts:
- ((1)/(49))^(1+log 7 2):
- We can rewrite (1/49) as 7^(-2).
- Applying the power of a power rule [(a^m)^n = a^(m*n)], we get: 7^(-2(1+log 7 2)).
- 5^(-log(15)7):
- This part involves a change of base for the logarithm.
Applying Logarithm Properties
1. Change of Base Formula:
* log(a)b = log(c)b / log(c)a, where c is any positive number other than 1.
Applying this to our expression:
- log(15)7 = log(7)7 / log(7)15 = 1 / log(7)15
Now, our expression becomes:
7^(-2(1+log 7 2)) + 5^(-1/log(7)15)
2. Simplifying further:
-
7^(-2(1+log 7 2)): Using the distributive property, we get 7^(-2 - 2log 7 2).
- Applying the power of a power rule again, we have 7^(-2) * 7^(-2log 7 2).
- Using the rule a^(-m) = 1/(a^m), we get 1/(7^2) * 1/(7^(2log 7 2)).
- Simplifying further: 1/49 * 1/(7^(log 7 2^2)).
- Utilizing the property a^(log a b) = b, we simplify to 1/49 * 1/2^2 = 1/196.
-
5^(-1/log(7)15): Using the rule a^(-m) = 1/(a^m), we get 1/(5^(1/log(7)15)).
Final Solution
Combining the simplified terms, the final simplified expression is:
1/196 + 1/(5^(1/log(7)15))
This is the simplest form of the original expression using the properties of logarithms and exponents.