Problem: The value of 10log10​7 is:
Answer Choices:
A. 7
B. 1
C. 10
D. log10​7
E. log7​10
Solution:
In general, aloga​N=N, with suitable restrictions on a and N;
or let 10log10​7=N. Taking logarithms of both sides of the equation to the base 10, we have log10​7⋅log10​10=log10​N.∴N=7.