NAME ____________________________________________ DATE _____________________________ PERIOD _____________

Chapter 7 REVIEW SCORE ___________ 1. Determine whether the function y = 0.3 !

!

! represents exponential growth or

decay.

2. Write an exponential function whose graph passes through the points (0, –5) and (–3, –40).

3. Solve 9!! ! ! = 243! ! !.

4. Solve !!

! ! != 16.

5. Solve 10! ! ! > 100!!!.

6. Write the equation 5!! = !!"#

in logarithmic form.

7. Evaluate log! 6!.

8. Evaluate log!128.

NAME ____________________________________________ DATE _____________________________ PERIOD _____________

9. Solve log!" x = !!.

10. Solve log! (2x + 5) ≤ log! (3x – 2).

Use 𝐥𝐨𝐠𝟓 2 ≈ 0.4307 and 𝐥𝐨𝐠𝟓3 ≈ 0.6826 to approximate the value of each expression. 11. log! 18 12. log! !

!

For Questions 14-19, solve each equation or inequality. If necessary, round to the nearest ten-thousandth. 13. log!n = !

! log! 64 + !

! log!49

14. log!(5 – 2a) – log!(3a) = 1 15. log!(x – 3) + log!(x + 2) = log!6 16. 7! ! ! = 80

NAME ____________________________________________ DATE _____________________________ PERIOD _____________

17. 3! = 6! ! !

18. 5!! ! ! < 30 19. Express log!"5 in terms of common logarithms. Then approximate its value

to the nearest ten-thousandth. 20. Suppose you deposit $500 in an account paying 4% annual interest,

compounded continuously. Use A = 𝑃𝑒!" to find the balance after 5 years. 21. Solve ln (x + 4) = 4. 22. Solve 𝑒!!! ≤ 18. 23. CHEMISTRY In 5 years, radioactivity reduces the mass of a 100-gram

sample of an element to 75 grams. Find the constant k for this element for t in years, then write the equation for modeling this exponential decay.

24. SAVINGS A savings account deposit of $300 is to earn 5.8% interest. After

how many years will the investment be worth $900? Use y = a (1 + 𝑟)!and round to the nearest tenth.

25. Evaluate (log!20!)( log!"5!).