Difference between revisions of "2015 AMC 12A Problems/Problem 14"
Line 14: | Line 14: | ||
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> | ||
+ | ==Video Solution== | ||
+ | Video starts at 1:04, uses the above solution: https://www.youtube.com/watch?v=OJyWHzjiu2A&t=44s | ||
== See Also == | == See Also == | ||
{{AMC12 box|year=2015|ab=A|num-b=13|num-a=15}} | {{AMC12 box|year=2015|ab=A|num-b=13|num-a=15}} |
Revision as of 17:41, 7 August 2020
Contents
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
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 |