Rewrite the logarithm as a ratio of common logarithms and natural logarithms. log4 (51) (a) common logarithms x (b) natural logarithms x A

log7 2401 x² 225 - MacBook A

Use properties of logarithms to condense the logarithmic expression and write it as a single logarithm. (No decimal answer).  log(A)−log(B)−log(?)

EXAMPLE 3 Magnitude of Earthquakes There are several other logarithmic scales used to calculate the magnitude of earthquakes. For instance, the U.S. Geological Survey uses the momert magnitude scale. The 1906 earthquake in San Francisco had an estimated magnitude of 8.3 on the Richter scale. In the same year a powerful earthquake occurred on the Colombia- Ecuador border that was four times as intense. What was the magnitude of the Colombia-Ecuador earthquake on the Richter scale?