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Resources Aops Wiki 2021 AMC 12A Problems/Problem 9: Revision history

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2021 AMC 12A Problems/Problem 9: Revision history

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27 September 2025

curprev 23:3123:31, 27 September 2025 MRENTHUSIASM talk contribs 9,193 bytes −1 →Solution 1
curprev 19:2619:26, 27 September 2025 Megacleverstarfish15 talk contribs 9,194 bytes −13 →Solution 1

10 September 2025

curprev 08:1408:14, 10 September 2025 MRENTHUSIASM talk contribs 9,207 bytes 0 →Solution 3 (Units digit and Multiples)

8 September 2025

curprev 22:3322:33, 8 September 2025 Pinotation talk contribs 9,207 bytes +28 →Solution 3
curprev 22:3222:32, 8 September 2025 Pinotation talk contribs 9,179 bytes +362 No edit summary

16 March 2025

curprev 16:4716:47, 16 March 2025 Hashbrown2009 talk contribs 8,817 bytes +264 →Solution 1

31 October 2024

curprev 02:0902:09, 31 October 2024 Yelechi talk contribs m 8,553 bytes 0 →Solution 6 (Generalization)

15 October 2024

curprev 22:1822:18, 15 October 2024 Prvb888 talk contribs 8,553 bytes −7 →Solution 4 (Engineer's Induction)

29 September 2024

curprev 11:2711:27, 29 September 2024 MRENTHUSIASM talk contribs 8,560 bytes −1 →Solution 8 (desperate & cheese) (similar to Solution 4)
curprev 08:4308:43, 29 September 2024 Neeyakkid23 talk contribs m 8,561 bytes +24 →Solution 8 (desperate & cheese)
curprev 08:4108:41, 29 September 2024 Neeyakkid23 talk contribs m 8,537 bytes +90 →Solution 8 (desperate & cheese): added clarification
curprev 08:4008:40, 29 September 2024 Neeyakkid23 talk contribs m 8,447 bytes +5 →Solution 8 (desperate & cheese): fixed grammar
curprev 07:2307:23, 29 September 2024 Neeyakkid23 talk contribs 8,442 bytes +804 New solution added

16 June 2023

curprev 09:2809:28, 16 June 2023 Thestudyofeverything talk contribs 7,638 bytes +29 →Video Solution

19 February 2022

curprev 20:3520:35, 19 February 2022 MRENTHUSIASM talk contribs m 7,609 bytes +15 →Solution 3
curprev 20:3120:31, 19 February 2022 MRENTHUSIASM talk contribs m 7,594 bytes 0 →Solution 6 (Generalization)
curprev 20:3120:31, 19 February 2022 MRENTHUSIASM talk contribs m 7,594 bytes +13 →Solution 3

5 January 2022

curprev 03:1103:11, 5 January 2022 MRENTHUSIASM talk contribs m 7,581 bytes 0 No edit summary

4 October 2021

curprev 20:3820:38, 4 October 2021 MRENTHUSIASM talk contribs m 7,581 bytes +2 →Solution 7 (Generalization)
curprev 20:3620:36, 4 October 2021 MRENTHUSIASM talk contribs m 7,579 bytes −24 →Solution 6 (Generalization)

18 August 2021

curprev 21:1921:19, 18 August 2021 MRENTHUSIASM talk contribs m 7,603 bytes −201 Sol 7 already did the same procedure 3 times. So, the rest can be omitted by \cdots.
curprev 21:1921:19, 18 August 2021 Dofl talk contribs m 7,804 bytes 0 →Solution 7 (Generalization)
curprev 21:1521:15, 18 August 2021 Dofl talk contribs m 7,804 bytes +6 →Solution 7 (Generalization)
curprev 21:1421:14, 18 August 2021 Dofl talk contribs m 7,798 bytes +195 →Solution 7 (Generalization)

3 July 2021

curprev 19:3319:33, 3 July 2021 Thelearningroyal talk contribs m 7,603 bytes +71 No edit summary

26 June 2021

curprev 23:5223:52, 26 June 2021 MRENTHUSIASM talk contribs m 7,532 bytes +4 →Solution 7 (Generalization)

15 June 2021

curprev 05:3505:35, 15 June 2021 MRENTHUSIASM talk contribs m 7,528 bytes 0 →Solution 7 (Generalization)
curprev 05:1605:16, 15 June 2021 MRENTHUSIASM talk contribs m 7,528 bytes 0 →Solution 7 (Generalization)
curprev 05:1405:14, 15 June 2021 MRENTHUSIASM talk contribs m 7,528 bytes +12 →Solution 7 (Generalization)
curprev 01:5901:59, 15 June 2021 MRENTHUSIASM talk contribs m 7,516 bytes −21 →Solution 7 (Generalization)
curprev 01:4901:49, 15 June 2021 MRENTHUSIASM talk contribs m 7,537 bytes −41 →Solution 7 (Generalization)

14 June 2021

curprev 20:0820:08, 14 June 2021 MRENTHUSIASM talk contribs m 7,578 bytes +168 →Solution 7 (Generalization)
curprev 18:1618:16, 14 June 2021 MRENTHUSIASM talk contribs m 7,410 bytes +49 →Solution 7 (Generalization)
curprev 17:4517:45, 14 June 2021 MRENTHUSIASM talk contribs 7,361 bytes +1,423 Added in Sol 7.
curprev 16:4616:46, 14 June 2021 MRENTHUSIASM talk contribs m 5,938 bytes −8 Removed extra pairs of parentheses.
curprev 16:1616:16, 14 June 2021 MRENTHUSIASM talk contribs m 5,946 bytes +1 →Video Solution by OmegaLearn (Factorizations/Telescoping& Meta-solving)
curprev 16:1616:16, 14 June 2021 MRENTHUSIASM talk contribs m 5,945 bytes +1 →Video Solution by OmegaLearn(Factorizations/Telescoping& Meta-solving)
curprev 16:1216:12, 14 June 2021 MRENTHUSIASM talk contribs 5,944 bytes +103 Reformatted: The boxes are consistent throughout the solutions. Also, I fixed Solution 6's spacing.

15 April 2021

curprev 08:2108:21, 15 April 2021 MRENTHUSIASM talk contribs m 5,841 bytes +1 →Solution 6(Generalization): Added in a space.

14 March 2021

curprev 14:1814:18, 14 March 2021 Bakedpotato66 talk contribs m 5,840 bytes +165 →Solution 1
curprev 01:1201:12, 14 March 2021 Kingravi talk contribs m 5,675 bytes −1 →Solution 6(Generalization)
curprev 01:1001:10, 14 March 2021 Kingravi talk contribs 5,676 bytes +1,425 No edit summary

7 March 2021

curprev 16:5016:50, 7 March 2021 Jackzhou talk contribs 4,251 bytes +85 →Video Solution by Aaron He
curprev 16:3716:37, 7 March 2021 Thestudyofeverything talk contribs 4,166 bytes −105 →Video Solution (Quick & Simple)
curprev 16:3516:35, 7 March 2021 Thestudyofeverything talk contribs 4,271 bytes +105 →Video Solution by Aaron He
curprev 16:3416:34, 7 March 2021 Thestudyofeverything talk contribs 4,166 bytes −106 →Video Solution (Quick and Simple)

5 March 2021

curprev 11:1911:19, 5 March 2021 Mathboy100 talk contribs 4,272 bytes +1 →Solution 5 (Difference of Squares)

4 March 2021

curprev 10:0610:06, 4 March 2021 Mathboy100 talk contribs 4,271 bytes +24 →Solution 5
curprev 10:0410:04, 4 March 2021 Mathboy100 talk contribs 4,247 bytes −4 →Solution 5
curprev 10:0410:04, 4 March 2021 Mathboy100 talk contribs 4,251 bytes +21 →Solution 5

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