Question

Multiply the polynomials (3y^3 + 2y^2 – 7y) and (2y^2 – 4y + 4).

Answer 1

6 y^5 - 8 y^4 - 10 y^3 + 36 y^2 - 28 y

Explanation:

Expand the following:

(3 y^3 + 2 y^2 - 7 y) (2 y^2 - 4 y + 4)

| | | | 3 y^3 | + | 2 y^2 | - | 7 y | + | 0

| | | | | | 2 y^2 | - | 4 y | + | 4

| | | | 12 y^3 | + | 8 y^2 | - | 28 y | + | 0

| | -12 y^4 | - | 8 y^3 | + | 28 y^2 | + | 0 | + | 0

6 y^5 | + | 4 y^4 | - | 14 y^3 | + | 0 | + | 0 | + | 0

6 y^5 | - | 8 y^4 | - | 10 y^3 | + | 36 y^2 | - | 28 y | + | 0:

Answer: 6 y^5 - 8 y^4 - 10 y^3 + 36 y^2 - 28 y