Might've been simpler to show that by putting a 5 in ANY of the available spots in row 3, they ALL eliminate the 5 at R1C8. Then you are left with only one spot in R1 for the 5.
I think a simpler spot is a "skyscraper" on 5s in row 1 and row 8. In row 1, 5 can only go in columns 6 and 8. In row 8, 5 can only go in columns 5 and 8. The important thing is that they both share column 8. Only one of R1C8 and R8C8 can be 5, meaning at least one of R1C6 and R8C5 must be a 5. So now we can look for cells that see both of those, i.e. R7C6 cannot be a 5 so must be a 2. This logic gets you to the same place since now R1C6 cannot be a 2 and must be a 5...
Might've been simpler to show that by putting a 5 in ANY of the available spots in row 3, they ALL eliminate the 5 at R1C8. Then you are left with only one spot in R1 for the 5.
I think a simpler spot is a "skyscraper" on 5s in row 1 and row 8.
In row 1, 5 can only go in columns 6 and 8. In row 8, 5 can only go in columns 5 and 8. The important thing is that they both share column 8. Only one of R1C8 and R8C8 can be 5, meaning at least one of R1C6 and R8C5 must be a 5. So now we can look for cells that see both of those, i.e. R7C6 cannot be a 5 so must be a 2.
This logic gets you to the same place since now R1C6 cannot be a 2 and must be a 5...
it's kind of like having 2 skyscrapers in 1, because if you consider only having one of either fin possible, you get skyscrapers.
The first thing I noticed here was an empty rectangle
hopefully you could rase your volume up on next video. would be great..thanks