Questions: Solving exponential equations

Author

Zoë Gemmell, Isabella Lewis, Akshat Srivastava

Summary
A selection of questions for the study guide on solving equations involving indices.

Before attempting these questions, it is highly recommended that you read Guide: Solving exponential equations.

Solve each of the exponential equations below for the variable in the equation. If an equation has more than one variable, solve for the variable stated.

  1. \(\quad\sqrt[4]{m-4}=5\)

  2. \(\quad x^4=2^8\)

  3. \(\quad 11^x=121^{(x-1)}\)

  4. \(\quad y^{0.5}=23\)

  5. \(\quad 8^{2-x}=2^{4+3x}\)

  6. \(\quad 2^{3x}=10\)

  7. \(\quad 5^{3-a}=625\)

  8. \(\quad 16^{2x}=4^{x-1}\)

  9. \(\quad 7^{2-x}=4^{2x+3}\)

  10. \(\quad 16=8^{3-7x}\)

  11. \(\quad e^{3-8p}-9=0\)

  12. \(\quad e^{4-3q}+8=12\)

  13. \(\quad \sqrt[3]{2^{4l}-4}=5\)

  14. \(\quad \sqrt[3]{e^{2h}-13}=81^{\frac{1}{4}}\)

  15. \(\quad \dfrac{5xa^{-7}b^{9}}{9a^2b^{-10}} = \dfrac{25b^{19}}{3a^9}\), solve for \(x\).

  16. \(\quad 4^x\cdot 2^x=64\)

  17. \(\quad {\dfrac{5^{x+1}\cdot6^{x+1}}{3^{x+1}}}=100\)

  18. \(\quad \dfrac{\left[\left(\frac{1}{2}\right)^x\cdot\left(\frac{-1}{4}\right)^x\right]}{\left(\frac{2}{3}\right)^x}=-\dfrac{27}{4096}\)

  19. \(\quad 3^{b+1}=7^b\)

  20. \(\quad 5^{x+1}+5^x=12\)

  21. \(\quad 2^{3z-1}=10^z\)

  22. \(\quad 2^{2v}-2^{v+3}-2^4=0\)


After attempting the questions above, please click this link to find the answers.


Version history and licensing

v1.0: initial version created 08/23 by Zoë Gemmell, Isabella Lewis, Akshat Srivastava as part of a University of St Andrews STEP project.

  • v1.1: edited 05/24 by tdhc.

This work is licensed under CC BY-NC-SA 4.0.

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