Which of the following value pairs can be used as m and n to factor the expression 4x^2 - 8x + 3?

A. 2, 6
B. –2, 6 C. 2, –6
D. –2, –6

Question

Which of the following value pairs can be used as m and n to factor the expression 4x^2 - 8x + 3?

A. 2, 6
B. –2, 6 C. 2, –6
D. –2, –6

hero · Answer

Hint: Find two numbers $m$ and $n$ so that:

$mn = 12$
$m + n = -8$

anonymous · Answer

I don't understand...

hero · Answer

Hint: Find two numbers m and n so that:

$m \times n = 12$
$m + n = -8$

Whatever $m$ and $n$ are, they must satisfy both conditions. It's a matter of FINDING the two numbers. You ask yourself, 

"What two numbers can I think of that would multiply to get 12, but also add to get -8?

anonymous · Answer

A? (2, 6)

hero · Answer

2 + 6 = -8 ?

anonymous · Answer

not negative 8. anything I try to add with it just adds to -4...

anonymous · Answer

Wait, -2 and -6

hero · Answer

Yes
-2 + -6 = -8 
(-2)(-6) = 12 

right?