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Well, hello I am spanish and I am newbie.

This is the dificult sudoku. It is few solve for me and it is correct because I have the solution, but I want learn :

Code: Select all

#####################################
# 2 | 9 | 5 # 7 |   |   # 8 | 6 |   #
#---+---+---#---+---+---#---+---+---#
#   | 3 | 1 # 8 | 6 | 5 # 9 | 2 |   #
#---+---+---#---+---+---#---+---+---#
# 8 |   | 6 #   |   |   #   |   |   #
#####################################
#   |   | 7 #   | 5 |   #   |   | 6 #
#---+---+---#---+---+---#---+---+---#
#   |   |   # 3 | 8 | 7 #   |   |   #
#---+---+---#---+---+---#---+---+---#
# 5 |   |   #   | 1 | 6 # 7 |   |   #
#####################################
#   |   |   # 5 |   |   # 1 |   | 9 #
#---+---+---#---+---+---#---+---+---#
#   | 2 |   # 6 |   |   # 3 | 5 |   #
#---+---+---#---+---+---#---+---+---#
#   | 5 | 4 #   |   | 8 # 6 | 7 | 2 #
#####################################


What is it the next step? and What is the tecnique used to next step?

Thanks. Bye

The key to solving it is row 4.

There are two groups of numbers. One group has the numbers 2, 3, 4, 9, and the other one has the numbers 1, and 8.

If you work out what that means then you will see that there is only one place for the number 3 in row 4.