Which property of polynomial subtraction says that the difference of two polynomials is always a polynomials

If a • b*2 = 1.8 x 10*-7, and c•b/d = 7.2 x 10*-4, find the value of a•d*2/c*2

Can someone me with this problem . show your work .

Sandy is ordering bread rolls for her party, she wants 3/5 of the rolls to be whole wheat. what other factions can represent part of the rolls that will be whole wheat? shade the models to show your work.