Predicate Logic Maximum

Question

If P(x,y) : the pixel on row x and column y is lit. How would I then express that:

1. Maximum one pixel is lit on every row

2. There is at least one row where exactly 1 pixel is lit.

I have tried using negation without effect. Do you have any tips to help me along the way?

It needs to be expressed as a closed predicate formula

Answer 1

1. In any row, there is a column and if any column in that row has a lit pixel, then that is it.

2. There is a row where there is a column where the pixel is lit, and no other column in that row has a lit pixel.

Say it with flowers symbols.