CHEMISTRY After 12 hours, half of a 16-gram sample of a radioactive element remains. Find the constant k for this element for t hours, then write the ...
3. Write an exponential function whose graph passes through the points (0, -6) and (-2, -54).
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4. Solve 94x + 4 = 2432x + 2.
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1 5. Solve − = 6 n + 4.
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6. Solve 32 x < 16 x + 2.
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6
1 1 7. Write the equation log81 − = -− in exponential form.
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8. Evaluate log9 97.
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9. Evaluate log4 128.
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9
2
3 10. Solve log36 n = − .
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11. Solve log5 (8x) > log5 (3x + 10).
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2
x
Use log5 2 ≈ 0.4307 and log5 3 ≈ 0.6826 to approximate the value of each expression. 12. log5 48
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5 13. log5 −
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3
Chapter 8
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Glencoe Algebra 2
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8
Chapter 8 Test, Form 2C
PERIOD
(continued)
For Questions 14–19, solve each equation or inequality. If necessary, round to the nearest ten-thousandth. 14.
15. log2 (2x + 6) - log2 x = 3
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16. log3 (x + 3) + log3 (x - 2) = log3 14
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17. 6 n - 2 = 50
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18. 2y = 5 y - 2
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19. 4 3x + 1 < 28
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20. Express log12 4 in terms of common logarithms. Then approximate its value to the nearest ten-thousandth.
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21. Suppose you deposit $3000 in an account paying 2% annual interest, compounded continuously. Use A = Pert to find the balance after 5 years.
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22. Solve ln (x - 5) = 3.
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23. Solve e-4x ≤ 9.
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24. CHEMISTRY After 12 hours, half of a 16-gram sample of a radioactive element remains. Find the constant k for this element for t hours, then write the equation for modeling its exponential decay.
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25. SAVINGS A savings account deposit of $150 is to earn 6.5% interest. After how many years will the investment be worth $450? Use y = a(1 + r) t and round to the nearest tenth.
