Answer: 2(2y+5)
Explanation:
One possible factorization is 2(2y+5)=4y+10, which would correspond to a set of dimensions 2 by (2y+5) for the rectangle.
Note that this is only one of many possibilities to come up with the dimensions. For example another possibility would be 1*(4y+10), or 4*(y+2.5). In fact, in Real numbers, there are infinitely many possible rectangles with a particular area.