Question

Which expression is equivalent to (x2 – 3x)(4x2 + 2x – 9)?

A. x2(4x2 + 2x – 9) – 3x
B. x2(4x2 + 2x – 9) – 3x(4x2 + 2x – 9)
C. x2(4x2 + 2x – 9) + 3x(4x2 + 2x – 9)
D. x2(4x2 + 2x) – 3x(2x – 9)

Answer 1

That would be  choice B.

Answer 2

Answer:

B. $x^2(4x^2 + 2x -9) -3x(4x^2 + 2x - 9)$

Step-by-step explanation:

The distributivity establish that in order to multiply these two polynomials, first you have to multiply $x^2$ by every element in  $4x^2 + 2x - 9$ and then multiply $-3x$ by every element in $4x^2 + 2x - 9$ as well.

That is exactly what the option B. says, since

in the expresion $x^2(4x^2 + 2x - 9) - 3x(4x^2 + 2x - 9)$ $x^2$ is being multiplied  by every element in  $(4x^2 + 2x - 9)$ and also $-3x$ is being multiplied by every element in  $(4x^2 + 2x - 9)$.