Multiply the polynomials (a^2 + 3a – 7) and (a + 4). simplify the answer. can you show your work so that i can know the step by step process?

Plz determine whether the polynomial is a difference of squares and if it is, factor it. y2 – 196 is a difference of squares: (y + 14)2 is a difference of squares: (y – 14)2 is a difference of squares: (y + 14)(y – 14) is not a difference of squares

Ill mark the brainliest if you me with the these three questions 7,8,9

Afarm that has 4 x 10^2 acres has 1.2 x 10^5 cattle. what is the average number of cattle per acre? write the answer in scientific notation. answere asap