# Unexpectedly Difficult Matchstick Problem

The words say:

note: it is not my puzzle and i do not know the solution • welcome to puzzling se May 10, 2020 at 7:11
• Are we allowed to rot13(cynpr n zngpu bire gur rdhnyf fvta ng na natyr gb znxr gur "qbrf abg rdhny" fvta)? If so, there are several solutions. May 10, 2020 at 7:15
• @LannyStrack if that were the case, this would be a very dull puzzle. Not sure if there are any actual solutions besides that, working on it May 10, 2020 at 7:19
• @OliverNi - It is not unheard of to have a trick question whose answer is dull (once you know the trick). May 10, 2020 at 7:19
• If you tried to solve this on an internet site with cookies then it tells advertisers you are someone who has a) time to waste b) you are a problem solver rather than a manager or something, therefore probably earning enough c) you are motivated by proving your intelligence. The correct answer therefore depends on what kind of ads you want to pop up everywhere when browsing the web. May 11, 2020 at 9:26

Remove the top left match of "9". Then the "9" becomes a "3". Place the removed match horizontally before "3". Then, it becomes "-3".
So, our equation becomes
-3+5=2

• I like that better than my answer. May 10, 2020 at 7:26
• Nice! how did i not see that?? May 10, 2020 at 7:27
• Congratulations @Sid. 200 IQ!
– DrD
May 10, 2020 at 12:49
• My solution was to take that one and put it over the equal sign, changing it to "not equal," but I like yours better. May 11, 2020 at 16:52

Move the top-right vertical match in the 2 to the top-left vertical position so that the right hand side forms an 'E'. The equation then becomes 9 + 5 = E, where E is 14 in the hexadecimal number system. 9 and 5 are represented the same in both decimal and hexadecimal, so the left hand side of the equation is unchanged.

• Found the computer nerd :-) May 12, 2020 at 12:58
• Definitely a +1 from me mainly because my first answer on the site also involved matches and a sneaky abuse of hex :) May 12, 2020 at 17:03

You can also

remove the vertical match from the plus sign and place it slanted over the equals sign to get $$9-5\neq2$$.

• the question does say "satisfy the equation" May 11, 2020 at 2:23
• The translation provided with the question does say "equation", but Google Translate says "算式" is "formula", so, if this is correct, I would say this answer qualifies.
– dhag
May 12, 2020 at 14:21

I am not sure if this is what the puzzle creator has in mind, but if you:

discard the match in the upper left (e.g., "moving" it by striking it so that it lights and then burns up), and then rotate yourself behind the puzzle looking at it upside down (equivalent to flipping the puzzle around an imaginary x-axis), it reads 3+2=5.

• rot13(Ybbxvat ng vg "sebz oruvaq" [fhpu nf sebz gur obggbz bs n tynff gnoyr] jba'g jbex orpnhfr gur 3 orpbzrf na R. Ohg hfvat n zveebe fubhyq jbex) May 10, 2020 at 19:44
• @BlueRaja-DannyPflughoeft - that is not what I wrote. Read the full answer. May 10, 2020 at 22:08
• wouldn't the 3 be backwards? May 11, 2020 at 3:03
• @SwissFrank - no. rotate it 180 degrees on the x-axis. still forwards. May 11, 2020 at 6:16

Another [lateral-thinking] option is

Tilt the upper match of the equals sign, making it into a greater than sign

• You beat me to it! This was the solution I saw. May 11, 2020 at 13:03
• The question does say "satisfy the equation".
– pts
May 11, 2020 at 23:41
• I'm probably going to regret asking this, but my mind is blanking. What's it called if you're not using "="? i.e. "9+5 > 2" ....... Is that a statement? or formula? What if you moved the left-top of the 9 to get "3+5 >= 2" (use imagination for >= as one sign please) - is that an equation? or a statement? (or whatever word I can't think of..) May 12, 2020 at 20:30
• @TCooper "inequality", although the starting "statement" is not already an inequality. May 12, 2020 at 22:05

I’m thinking hexadecimal here. Therefore 9+5=E, in Base16. >!One matchstick from 2 to E.

• Welcome to Puzzling.SE! I'm afraid somebody already beat you to this answer: puzzling.stackexchange.com/a/98050/31839 May 12, 2020 at 10:59
• That’s cool, just wanted to participate. My first time here in this particular community. May 12, 2020 at 11:08
• @JoeyGodwin please "spoilerize" any answer you post in this group. See the "help" section for formatting tips May 12, 2020 at 12:59

I saw this once and a solution I saw was

Remove a match from the 9 to make it a 3. Then put that extra match over the equals sign to make a not equals sign (≠)