### Home > CCA2 > Chapter 7 > Lesson 7.1.3 > Problem7-39

7-39.

Given that log 2 ≈ 0.3010, log 3 ≈ 0.4771 and log 5 ≈ 0.6990, calculate each of the following logarithms without using a calculator. Homework Help ✎

 a. log 6 b. log 15 c. log 9 d. log 50

log 6 = log (2⋅3)
Now use the properties of logs to expand.

log2 + log3 ≈ 0.7781

Express 15 as a product of numbers whose logs are given.

See part (a).

log 9 can be rewritten as log(3 · 3) or log 32. Try both.

50 = 2 · 52