### Home > A2C > Chapter 7 > Lesson 7.2.2 > Problem 7-113

7-113.

Use the definition of a logarithm to change log_{2}7 into a logarithmic expression of base 5. Homework Help ✎

Start with the definition of the logarithm.

log_{2}7 = *x*

2* ^{x}* = 7

Take the log base 5 of both sides.

log_{5}(2* ^{x}*) = log

_{5}7

Use the power property.*x*(log_{5}2) = log_{5}7

Notice that this answer shows a very quick way to change bases.