Question

(x + 3)(9x² + x + 1) =

a. 9x³ + 28x² + 4x + 3
b. 9x³ + 13x² + 4x + 3
c. 9x³ + 27x² + 3x + 3
d. 9x³ + 28x² + 3x + 4

type in the letter of the correct choice: a, b, c or d

Explanation:

Step1: Apply distributive property (FOIL for polynomials)

Multiply \(x\) by each term in \(9x^2 + x + 1\) and \(3\) by each term in \(9x^2 + x + 1\):
\(x(9x^2 + x + 1)=9x^3 + x^2 + x\)
\(3(9x^2 + x + 1)=27x^2 + 3x + 3\)

Step2: Combine like terms

Add the two results together:
\((9x^3 + x^2 + x)+(27x^2 + 3x + 3)=9x^3+(x^2 + 27x^2)+(x + 3x)+3=9x^3 + 28x^2 + 4x + 3\)

Answer:

A