CPM Homework Help : CCA2 Problem 8-124

Now divide $x^3 - 9x^2 + 19x + 5$ by the factor that you chose in the preceding problem. If it is a factor, use it and the resulting factor to find all the zeros of the polynomial. If it is not a factor, reconsider your answer to the preceding problem and try a different factor.

Step 1:

2 by 3 rectangle, labeled as follows: left edge, x, minus 5, interior top, left, x, cubed.

Step 2:

Labels added: Top edge, left, x, squared, interior bottom, left, negative 5, x, squared, interior top, middle, negative 4, x squared.

Step 3:

Labels added: Top edge, middle, negative 4, x, interior bottom, middle, 20, x, interior top, right, negative, x.

Partial Answer:

Labels added: top edge, right, negative 1, interior bottom, right, 5.

$x^3 − 9x^2 + 19x + 5 = (x - 5)(x^2 - 4x - 1)$

Step 4:

$x − 5 = 0$
$x^2 - 4x − 1 = 0$

Now finish solving.