The sum of two polynomials is 8d5 – 3c3d2 + 5c2d3 – 4cd4 + 9. If one addend is 2d5 – c3d2 + 8cd4 + 1, what is the other addend?

6d5 – 2c3d2 + 5c2d3 – 12cd4 + 8
6d5 – 4c3d2 + 3c2d3 – 4cd4 + 8
6d5 – 4c3d2 + 5c2d3 – 12cd4 + 8
6d5 – 2c3d2 – 3c2d3 – 4cd4 + 8

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.

All you have to do is multiply