Isaac's answer is correct.
To check, we can use the FOIL method to multiply the factors:
(8x+4)(x-3) = 8x(x) + 8x(-3) + 4(x) + 4(-3)
= 8x^2 - 24x + 4x - 12
= 8x^2 - 20x - 12
Therefore, the factors (8x+4)(x-3) do simplify to the original polynomial expression 8x^2-20x-12.
Isaac was asked to factor the following expression completely:
8x^2-20x-12
Isaac got (8x+4)(x−3) as their answer and claims it is correct because when multiplying the factors it simplifies to the original polynomial expression.
Is Isaac correct? Why or why not?
3 answers
wrong
better would be
4(2x+1)(x-3)
4(2x+1)(x-3)