Number 2 is the only value possible in cell (7,4).

Number 3 is the only value possible in cell (3,4).

Number 1 is the only value possible in cell (2,4).

Number 7 is the only value possible in cell (5,4).

Number 5 is the only value possible in cell (5,6).

Number 8 is the only value possible in cell (7,6).

Number 6 is the only value possible in cell (3,6).

Number 7 is the only value possible in cell (8,6).

For column 1, Number 2 is only possible in cell (1,7)

For column 9, Number 7 is only possible in cell (9,7)

For column 6, Number 7 is only possible in cell (6,8)

For row 1, number 6 is only possible in cell (7,1)

For row 9, number 6 is only possible in cell (1,9)

For column 4, Number 5 is only possible in cell (4,8)

For box 9, Number 8 is only possible in cell (8,7)

Number 9 is the only value possible in cell (3,7).

For row 8, number 9 is only possible in cell (5,8)

For box 9, candidates for 4 are all in column 7, so you can remove candidates from other blocks.

For blocks 6 and 9, candidates for 5 are all in the same two columns (7 and 8)

X-Wing in columns for 3.

Number 7 is the only value possible in cell (2,9).

Number 4 is the only value possible in cell (3,9).

Number 8 is the only value possible in cell (1,8).

Number 4 is the only value possible in cell (1,3).

Number 3 is the only value possible in cell (2,8).

Number 4 is the only value possible in cell (7,8).

For row 3, number 7 is only possible in cell (3,3)

For row 3, number 5 is only possible in cell (9,3)

For row 2, number 5 is only possible in cell (3,2)

For row 2, number 2 is only possible in cell (8,2)

For row 2, number 9 is only possible in cell (6,2)

For row 3, number 8 is only possible in cell (2,3)

Number 2 is the only value possible in cell (3,1).

Number 9 is the only value possible in cell (2,1).

Number 3 is the only value possible in cell (8,1).

Number 8 is the only value possible in cell (5,1).

Number 4 is the only value possible in cell (9,1).

Number 1 is the only value possible in cell (5,2).

Number 4 is the only value possible in cell (4,2).

Number 8 is the only value possible in cell (9,2).

Number 9 is the only value possible in cell (7,3).

Number 2 is the only value possible in cell (2,5).

Number 8 is the only value possible in cell (3,5).

Number 3 is the only value possible in cell (4,5).

Number 6 is the only value possible in cell (4,3).

Number 3 is the only value possible in cell (6,3).

Number 4 is the only value possible in cell (6,5).

Number 5 is the only value possible in cell (7,5).

Number 9 is the only value possible in cell (8,5).

Number 1 is the only value possible in cell (4,7).

Number 6 is the only value possible in cell (6,7).

Number 3 is the only value possible in cell (7,7).

Number 3 is the only value possible in cell (5,9).

Number 1 is the only value possible in cell (7,9).

Number 5 is the only value possible in cell (8,9).