Solve each exponential equation for x.

1. $10^x=16$ 

   Hint (a):

   Rewrite it in $k=\log_bN$ format.

   Step (a):

   Use your calculator for $\log_{10}16$.

2. $10^x=41$ 

   Hint (b):

   See part (a).

3. $3^x=729$ 

   Hint (c):

   What are some powers of $3$? $3^4,3^5,...$

4. $10^x=101$ 

   Hint (d):

   See part (a).