Example: <span>the second step in the process for factoring the trinomial x^2-3x-40 is to:</span> <span>Well you really should find the sum of the factors of −40 (not 40) </span>
<span>But before you can do that, you need to LIST the factors of −40 (not 40) </span>
<span>−1 * 40 </span>
<span>−2 * 20 </span>
<span>−4 * 10 </span>
<span>−5 * 8 </span>
<span>−8 * 5 </span>
<span>−10 * 4 </span>
<span>−20 * 2 </span>
<span>−40 * 1 </span>
<span>NOW we find the sum of the factors of −40 </span>
<span>−1 + 40 = 39 </span>
<span>−2 + 20 = 18 </span>
<span>−4 + 10 = 6 </span>
<span>−5 + 8 = 3 </span>
<span>−8 + 5 = −3 </span>
<span>−10 + 4 = −6 </span>
<span>−20 + 2 = −18 </span>
<span>−40 + 1 = −39 </span>
<span>Then we choose the factors of −40 whose sum is −3 ---> −8 and 5 </span>
<span>x^2 − 3x − 40 = (x − 8) (x + 5) </span>
<span>So FIRST step is B, SECOND step is C, and final step is factoring. </span>
What Rita did was combine these 2 steps together, which you will learn to do as you get better at factoring.
I want to say A because 3 and 5 have 15 and 6:15 is sounds like a ratio and D is just 4/10
