Pearson Algebra 2 Common Core, 2011
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Pearson Algebra 2 Common Core, 2011 View details
4. Rational Expressions
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Exercise 59 Page 533

Set up an equation and apply the definition of a logarithm.

3/2

Practice makes perfect
To evaluate the given logarithm, we will start by writing a logarithmic equation. log_5 5sqrt(5)=x In order to solve this equation, we can rewrite it as an exponential equation by using the definition of a logarithm. log_b x= y ⇔ x= b^y The above means that the logarithm y is the exponent to which b must be raised to get x. For our exercise, x is the exponent to which 5 must be raised to get 5sqrt(5). log_5 5sqrt(5)= x ⇔ 5sqrt(5)= 5^x Finally, to solve the exponential equation, we will rewrite the terms so that they have a common base.
5sqrt(5)=5^x
5* 5^(12) = 5^x
5^(1+ 12) = 5^x
Now we have two equivalent expressions with the same base. If both sides of the equation are equal, the exponents must also be equal.
5^(1+ 12) = 5^x
1+1/2 = x
2/2+1/2 = x
3/2 = x
x = 3/2