Question

Hank’s teacher asked him to verify that the product (y – 3)(y2 + 3y + 9) is a difference of cubes. He used the distributive property to multiply the binomial times the trinomial. Before simplifying, his product was a polynomial of the form y3 + 3y2 + ay – 3y2 – ay – 27. What is the value of a in the polynomial?

Answer 1

a little tedious but just apply the distributive property and see what your y-terms are

for example, distributing the y first gives us

y^3 + 3y^2 + 9y
so compare this to
y3 + 3y2 + ay

what would the a value be?