## help solving

Advanced methods and approaches for solving Sudoku puzzles

### help solving

my first week doing sudoku. did fine till my 1st hard puzzle. got this far, how do i proceed. i am totally unfamiliar with any of the lingo about solving, except for pencilmarks. thanks for your patience and help.

--- 4-- 5-8
--- 9-8 --7
-86 5-- ---
-9- 645 --3
125 837 6--
463 192 785
--- 2-- 35-
23- 754 ---
--1 3-9 -7-
sfddoc

Posts: 17
Joined: 14 August 2005

Try this:

In R7C9 the 1 can be excluded because the bottom middle box has the 1's restricted to R7.

In R8C8 the 6 can be excluded because the top right box has the 6's restricted to C8.

This should get you well on your way.
Xenon

Posts: 6
Joined: 15 August 2005

xenon, thanx so much, you showed me a new strategy i had not recognized.
sfddoc

Posts: 17
Joined: 14 August 2005

xenon, please help again, with your technique i could only eliminate one other pencil mark and still cant get farther, tell me more if you would, thanx so much.
sfddoc

Posts: 17
Joined: 14 August 2005

Assuming your additional placement is in r9c9, there's a pair in row 8, and another in block 9, and then it gets very easy.

Simes
simes

Posts: 324
Joined: 11 March 2005
Location: UK

simes, i do so appreciate your help, but i do not understand what you are telling me. r9c9 can still be 2, 4 0r 6. what do you mean by a pair? can you take me through a few more steps in this puzzle. thanx again.
sfddoc

Posts: 17
Joined: 14 August 2005

I normally understand what simes says, but this time I think he's gone mental.

If I might suggest something, how many places can you put a 6 in row 8? Following from this, you have a pair ({4,9} twice) in column nine - which means 4 and 9 can't be anywhere else in that column, so r9c9 is... Aaahh, now I think I know what simes did.

It pretty much opens up after that.
Karyobin

Posts: 396
Joined: 18 June 2005

Errrr.... I think I must have posted into the wrong thread. Which means I have to find where that answer was supposed to go.

Sorry for the confusion.

S
simes

Posts: 324
Joined: 11 March 2005
Location: UK

thank you karyobin, i am making progress, hopefully i can complete this, it really bugs one not to finish
sfddoc

Posts: 17
Joined: 14 August 2005