8-28 even Skills and Applications Writing an Exponential Equation In Exercises 7-10, write the logarithmic equation in exponential form. For example, the exponential form of log, 25 = 2 is 51 = 25. (7. log, 16 = 2 8. log, - -2 9. 10g 34- 10. log4 8- Writing a Logarithmic Equation In Exercises 11-14, write the exponential equation in logarithmic form. For example, the logarithmic form of 23 = 8 is log, 8 = 3. 11. 53 - 125 12. 93/2 = 27 13. 4-3 - 64 14. 240 = 1 Evaluating a Logarithmic Function In Exercises 15-20, evaluate the function at the indicated value of x without using a calculator. Function Value 15. f(x) = log, X x = 64 16. f(x) = log25 X *= 5 17. f(x) = logg x 18. f(x) = log x * = 10 19. g(x) = log, x 20. g(x) = log, x 1=b-3 Evaluating a Common Logarithm on a Calculator In Exercises 21-24, use a calculator to evaluate f(x) = log x at the indicated value of x. Round your result to three decimal places. 21. x= 22. x = 30 23, x = 12.5 5 24. x = 96.75 Using Properties of Logarithms In Exercises 25-28, use the properties of logarithms to simplify the expression. 25. log 117 26. log3 2 1 27. log- T 28. 9log, 15