Section 3.2 Question 16 [ATTACH=full]664[/ATTACH] How is 16 done without a calculator?

f(x)=log (25, x) x=5 f(x)=log (25, 5) f(x)= log(5)/log(25) f(x)= log(5)/log(5^2) f(x)= log(5)/(2log(5)).........simplify f(x) = 1/2

Let me see if I can do 18. f(x) = log x, where x = 10. f(x) = (10, 10) f(x) = log (10)/log (10) f(x) = 1/1 f(x) = 1