Question

Which of the following is the complete factorization of 3x2 - 6x - 240?



3(x - 2)(x - 80)
3(x + 8)(x - 10) *******
3x(x - 2)(x - 10)

Answer 1

Which one when multiplied out gives you \(3x^2-6x-240\)? That's the test...

Answer 2

the one with the *************

Answer 3

Then that is correct :-)

Answer 4

If we have factored out the 3, we're left with
\[x^2-2x-80\]The factors have to sum to -2 and multiply to -80. Of the three choices, +8 and -10 are the only ones that fit those constraints, so 3(x+8)(x-10) is correct.

Answer 5

With a little practice, you'll be confident enough in your work that you won't have to ask us if you did it right.