A quadratic expression, x^2+ax+20, can be factorized. Find all possible values for a. a can be positive or negative.

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.

4x 20 is 80 but if ther machine is broken then there is none you have to redo the test