Question

Multiply: (9x + 8) (3x² + x − 1)

O 27x³ + 9x² - 8
O 27x³ + 33x² + 17x + 8
O 3x² + 10x + 7
O 27x³ +33x² - x - 8​

Answer 1

`\textsf{D)} \quad 27x^3+33x^2-x -8`

Explanation:

Given expression:

`(9x+8)(3x^2+x-1)`

Distribute the parentheses:

`\implies 9x \cdot 3x^2+9x \cdot x+ 9x \cdot (-1) + 8 \cdot 3x^2 + 8 \cdot x +8 \cdot(-1)`

Simplify:

`\implies 27x^3+9x^2-9x + 24x^2 + 8x -8`

Collect like terms:

`\implies 27x^3+9x^2+ 24x^2-9x + 8x -8`

Combine like terms:

`\implies 27x^3+33x^2-x -8`