Simplify (x + 2)(x2 − 4x − 9).

x3 − 2x2 − 17x − 18
x3 − 6x2 − x − 18
x3 − 4x2 − 3x − 18
x3 − 10x2 − 9x − 18

Option A  x³ - 2x² - 17x - 18

Step-by-step explanation:

We have to simplify the given expression

(x+2) (x² - 4x - 9)

x(x² - 4x - 9) + 2 (x²- 4x - 9) [distributive Law]

=  x³ - 4x² - 9x + 2x² - 8x - 18

Now we accumulate similar terms together.

= x³ - 4x² + 2x² - 9x - 8x - 18

= x³ - 2x² - 17x - 18

This simplified form of the expression matches with option A.

Option A  x³ - 2x² - 17x - 18

step-by-step explanation:

first, eliminate the parenthesis:

3

x

+

2

−

4

x

second, group like terms:

3

x

−

4

x

+

2

third, combine like terms:

(

3

−

4

)

x

+

2

→

−

1

x

+

2

→

−

x

+

2