Is there a greatest common factor (GCF) between all of the terms in the given expression? If so, you should factor that out first.
A
Practice makes perfect
To determine which of the given expressions is a factor of the given quadratic trinomial of the form ax^2+bx+c, we first want to factor the trinomial completely.
To do this we will rewrite the middle term, bx, as two terms. The coefficients of these two terms will be factors of ac whose sum must be b.
6x^2+7x-20
⇕
6x^2+7x+(- 20)
We have that a= 6, b=7, and c=- 20. There are now three steps we need to follow in order to rewrite the above expression.
Find a c. Since we have that a= 6 and c=- 20, the value of a c is 6* (- 20)=- 120.
Find factors of a c. Since ac=- 120, which is negative, we need factors of a c to have opposite signs in order for the product to be negative. Since b=7, which is positive, the absolute value of the positive factor will need to be greater than the absolute value of the negative factor.
