Hi there!
We are given the equation 20 + 6c - 2c², and are told to factor it. Well, to do this, we can first rearrange the terms in decreasing order: -2c² + 6c + 20. Next, we see that we can take out a common factor -2 from the whole equation. This gives us -2(c² - 3c - 10). Now, we take the constant term, -10, and we find all it's factors.
-1 10
-10 1
-5 2
-2 5
Now, find the sums of the factors.
-1 + 10 = 9
-10 + 1 = -9
-5 + 2 = -3
-2 + 5 = 3
We see that the only pair of factors that add up to -3 are -5 and 2. Now, we can factor the whole equation to -2(c + 2)(c - 5). Hope this helped!
