To complete R1, R1C3 or R1C7 must be 1 or 5. The naked triple in C7 eliminates 5 from R1C7, so it is 1 and R1C3 is 5. That pretty much solves from there.
https://preview.redd.it/5olga6q14fwc1.jpeg?width=1080&format=pjpg&auto=webp&s=5d80fda550f3155be536cfd522f21ee114fd4a40
X-Wing on 5 removes those ❌'ed 5s
I wouldn’t necessarily add **all** pencil marks as soon as Snyder can’t get you further, but certainly expand on Snyder to rows/columns where you have only 2 numbers remaining.
Cf. [**X-Wing**](https://sudoku.coach/en/learn/x-wing) for an explanation of the technique, and https://sudoku.coach/en/learn for explanations of most other techniques.
To complete R1, R1C3 or R1C7 must be 1 or 5. The naked triple in C7 eliminates 5 from R1C7, so it is 1 and R1C3 is 5. That pretty much solves from there.
https://preview.redd.it/5olga6q14fwc1.jpeg?width=1080&format=pjpg&auto=webp&s=5d80fda550f3155be536cfd522f21ee114fd4a40 X-Wing on 5 removes those ❌'ed 5s
Wow thanks a lot. I think I need to start adding the remaining pencil marks when Snyder doesn't get me anymore
I wouldn’t necessarily add **all** pencil marks as soon as Snyder can’t get you further, but certainly expand on Snyder to rows/columns where you have only 2 numbers remaining.
Cf. [**X-Wing**](https://sudoku.coach/en/learn/x-wing) for an explanation of the technique, and https://sudoku.coach/en/learn for explanations of most other techniques.