Which expression is equal to 2x + 4 (3x - 2) for all possible values of x?

14x + 4

3 (x + 3)

2 (7x - 4)

20x + 16

Answer: 2 (7x - 4)

Explanation:

First let's distribute the 4 to (3x - 2) by multiplying each term by 4.

2x + 4 (3x - 2) =

2x + 4 • 3x - 4 • 2 =

2x + 12x - 8

Next we combine like terms:

2x + 12x - 8 =

14x - 8

None of the answers without parenthesis match the formula above so I will factor out a 2

14x - 8

= 2 (7x - 4)

Notice how I factored out the 2 putting the result of dividing the equation by 2 inside the parenthesis and then moving a 2 to the outside of the parenthesis.