Question

(someone please help me)

multiply the polynomials
(3x2 + 5x + 9)(6x - 8)

A. 18x3 + 6x2 - 104x - 72
B. 18x3 + 6x2 - 14x - 72
C. 18x3 - 6x2 + 14x - 72
D. 18x3 + 6x2 + 14x - 72​

Answer 1

Answer:

D

Steps:

Multiply the first term by each term in the second set of parentheses;

3x^2 * 6x = 18x^3

3x^2 * -8 = -24x^2

Now multiply the second term (and third term) by each term in the second set of parentheses;

5x * 6x = 30x^2

5x * -8 = -40x

9 * 6x = 54x

9 * -8 = -72

Then combine all the results;

18x^3 - 24x^2 + 30x^2 - 40x + 54x - 72

And combine like terms;

18x^3 + 6x^2 + 14x - 72