NYT Sudoku - hard

[HarraKiri]

Does anyone play the NYT sudoku (or even any sudoku?!). I've attached a pic of todays. The yellow square is the "hint" (I.e. I should be able to figure out what number goes there from the info on the board). I've revealed the square so I know what the answer is (9), but I don't know WHY it's 9, or what info im missing to figure it out! Can anyone tell me what deductions im not doing in order to figure this one out?! Pic should be attached

In that box the top three squares have to be 2,5 and 7. That means the bottom row have to be 1,3 and 9. It can't be 1 or 3 so must be 9

Oh you're a star!! My brain wasn't braining and for the life of me I couldn't see WHY that had to be the answer, I totally see what I was missing now, thank you.

The 9 has to be somewhere on the bottom row of that block. The other two in that row have to be 1 and 3 because of how the rows and columns they're in intersect.