Difference between revisions of "2015 AMC 12A Problems/Problem 14"
Pi is 3.14 (talk | contribs) (→Video Solution) |
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<cmath>\log_a 24 = 1.</cmath> | <cmath>\log_a 24 = 1.</cmath> | ||
Hence <math>a = 24</math>, and the answer is <math>\textbf{(D)}.</math> | Hence <math>a = 24</math>, and the answer is <math>\textbf{(D)}.</math> | ||
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+ | == Video Solution == | ||
+ | https://youtu.be/RdIIEhsbZKw?t=482 | ||
+ | |||
+ | ~ pi_is_3.14 | ||
==Video Solution== | ==Video Solution== |
Latest revision as of 04:27, 21 January 2021
Problem
What is the value of for which ?
Solution
We use the change of base formula to show that Thus, our equation becomes which becomes after combining: Hence , and the answer is
Video Solution
https://youtu.be/RdIIEhsbZKw?t=482
~ pi_is_3.14
Video Solution
Video starts at 1:04, uses the above solution: https://www.youtube.com/watch?v=OJyWHzjiu2A&t=44s
See Also
2015 AMC 12A (Problems • Answer Key • Resources) | |
Preceded by Problem 13 |
Followed by Problem 15 |
1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 • 16 • 17 • 18 • 19 • 20 • 21 • 22 • 23 • 24 • 25 | |
All AMC 12 Problems and Solutions |