How to write functions in factored form?
5x2 + 20x + 15
(5x2 is 5 to the second power) idk how to do these help :(
- AngelaLv 57 years agoFavorite Answer
5x^2 + 20x + 15
First, factor out the 5
5(x^2 +4x +3)
Now, let's work on what is in the parentheses. There are many ways to do it, but let's start with the "easiest" (in some people's opinion).
What 2 numbers multiplied together equals 3 but added together equals 4? Answer: 3 and 1.
^^ The reason for the question above is basically the reverse of FOIL, aka factoring.
So you final answer is...
5 (x+1) (x+3)
If in the future you come across numbers to large to do the "easiest" method OR if there is a # in front of x^2 that is not 1, just us the quadratic formula....It will solve it every time.