Difference between revisions of "2020 AMC 12B Problems/Problem 2"
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<cmath>\frac{100^2-7^2}{70^2-11^2} \cdot \frac{(70-11)(70+11)}{(100-7)(100+7)} = \frac{(100-7)(100+7)}{(70-11)(70+11)} \cdot \frac{(70-11)(70+11)}{(100-7)(100+7)}.</cmath> | <cmath>\frac{100^2-7^2}{70^2-11^2} \cdot \frac{(70-11)(70+11)}{(100-7)(100+7)} = \frac{(100-7)(100+7)}{(70-11)(70+11)} \cdot \frac{(70-11)(70+11)}{(100-7)(100+7)}.</cmath> | ||
Cancelling all the terms, we get <math>\boxed{\textbf{(A) } 1}</math> as the answer. | Cancelling all the terms, we get <math>\boxed{\textbf{(A) } 1}</math> as the answer. | ||
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+ | == Video Solution (HOW TO CREATIVELY THINK!!!)== | ||
+ | https://youtu.be/2z8MaCeqIKs | ||
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+ | ~Education, the Study of Everything | ||
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== Video Solution == | == Video Solution == | ||
https://youtu.be/WfTty8Fe5Fo | https://youtu.be/WfTty8Fe5Fo | ||
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== See Also == | == See Also == | ||
{{AMC12 box|year=2020|ab=B|num-b=1|num-a=3}} | {{AMC12 box|year=2020|ab=B|num-b=1|num-a=3}} | ||
{{MAA Notice}} | {{MAA Notice}} |
Latest revision as of 14:00, 8 June 2023
Contents
Problem
What is the value of the following expression?
Solution
Using difference of squares to factor the left term, we get Cancelling all the terms, we get as the answer.
Video Solution (HOW TO CREATIVELY THINK!!!)
~Education, the Study of Everything
Video Solution
See Also
2020 AMC 12B (Problems • Answer Key • Resources) | |
Preceded by Problem 1 |
Followed by Problem 3 |
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 |
The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions.