Question

What is a correct expansion of (4x+1)(2x^2-2)

A. 4x*2x^2+4x*(-2)+1*2x^2+1*(-2)
B. 4x*2x^2+4x*(-2)+1*4x+1*(-2)
C. 4x*2x^2+4x*(1)+1*2x^2+1*(-2)

Answer 1

Answer: B. 4x*2x^2+4x*(-2)+1*4x+1*(-2)

Step-by-step explanation: Hope this help :D

Answer 2

A. 4x * 2x^2 + 4x * (-2) + 1 * 2x^2 + 1 * (-2)

Explanation:

We have the binomial (4x + 1)(2x^2 - 2) and are asked to see how it looks like expanded.

When solving binomials, we need to follow the FOIL method :

First - First number in first parenthesis multiplied by first number in second parenthesis

Outer - First number in first parenthesis multiplied by second number in second parenthesis

Inner - Second number in first parenthesis multiplied by first number in second parenthesis

Last - Second number in first parenthesis multiplied by second number in second parenthesis

If we follow the definitions given, we can find our correct answer and also see where all the other answers mess up at :

A. 4x*2x^2+4x*(-2)+1*2x^2+1*(-2)

This follows FOIL entirely from start to finish.

B. 4x*2x^2+4x*(-2)+1*4x+1*(-2)

This did not follow the Inner part of FOIL.

C. 4x*2x^2+4x*(1)+1*2x^2+1*(-2)

This did not follow the Outer part of FOIL.