Adding= sum what are those kind of words for subtract divide and multiply? i am not for sure what they are called.

Adding = sum, quantity
dividing = quotient, divided by
subtract = less then, difference
multiply = product, times a number

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.