What is the value of the y determinate 3x plus y -10 equals zero and 4x minus y -4 equals zero

The first one, i believe, would be correct. all the others have one thing in common, and that's that they have repeating numbers. in the second one, x and y have repeating 6's and 3's, and in the third, x and y have repeating 6's as well. in the last one, there are repeating 3's. the first one has no repeating numbers.

The correct answer is addition

So confused right here i need it to be more clearer