Thats a very tricky one at first I thought not too bad but then realised you can repeat the same number in a row or column. To be honest I think it just needs a lot of time and effort to solve.
Oh no
I was expecting a regular Sudoku type puzzle too, but this one is evil!
Even if there is a lot of trial and error there must be some ways to narrow down my choices?
I would tend to manage them as equations with variables.
So you take the first row and you say that the rest add up to 26, so the remaining three add up to 21. Or "a3 + a6 + a10 = 21"
Then you find other rows where these things are specified (like the last row), to get another equation such as
a10 + f10 + g10 = 20
You can then do substitutions - sub in the top row and you get
a3 + a6 + (20 - f10 - g10) = 21
Then build up crazy equations from there and hopefully at some point you will come out with something that says a3 = 6. Then you can plug that into the equations you've already made and get answers for everything.
Maybe that's the wrong way to go about it, but it's all I can see.
I like your idea with the equations one problem I see though. There is 34 blanks, including the ones with letters in them, and you would get 22 equations. If I'm not mistaken you need the same amount or more equations than unknowns to solve it, could be wrong here but pretty sure that is the rule.
I'd wonder a bit looking at the comments is there a unique solution, owner says they have edited it but I'd still be bit sceptical.
If you know anyone who does a bit of programming shouldbe easy enough for them to solve with simple program.
