The New Sudoku Players' Forum

[WABJABUSC$UC]

XX7 14X 936
936 7X8 4XX
4X1 639 XXX

7XX XXX 694
X94 2X6 XXX
61X 49X XX2

X6X 3XX X49
X48 96X 75X
X79 XX4 X6X

[daj95376]

You need to read up on Locked Candidates. The remaining solution needs:

4* Locked Candidates (1)
1* Locked Candidates (2)
1* Naked Pair
** Naked/Hidden Singles

[ravel]

In block 9 the 2 must be in c7, therefore r3c7<>2.
In columns 3 and 6 the 3 can only be in rows 4 and 6 (x-wing). Therefore r6c7<>3.
This leaves a naked pair 58 in r36c7.
Then r9c9 is the only place for an 8 in block 9.

Without x-wing:
In block 7 3 must be in column 1, therefore r5c1<>3.
Then in row 5 3 must be in block 6, therefore not in r6c7 (same block).