Find the product of the polynomial?

Question

(x + 3)(x2 – 3x + 2)

(x + 3)(x^2 – 3x + 2)

Answer 1

Just multiply through:
(x + 3)(x² - 3x + 2)

Start with distributing the x through:
x (x² - 3x + 2) = x^3 - 3x² + 2x

Then multiply the 3 through:
3 (x² - 3x + 2) = 3x² - 9x + 6

Now add the two together:
x^3 - 3x² + 3x² + 2x - 9x + 6

Cancel the 3x² terms:
x^3 + 2x - 9x + 6

Group the like terms:
x^3 - 7x + 6

There's your answer.

It often helps to write this in a grid:
......... x² .... -3x ...... 2
....... -----------------------------
x --> x^3 .. -3x² .. +2x
3 --> ......... 3x² ... -9x .. +6
....... -----------------------------
....... x^3 ....0x² ... -7x .. +6

Notice how you then ignore the 0x² term to get:
x^3 - 7x + 6