Hi there! I'm going to assume you mean m^2 + m - 20. The factor of this is (m + 5)(m - 4) And I found this by finding what two numbers add to 1 and multiply to -20, which is 5 and -4.
Now if you FOIL this, (First, outer, inner, last terms) you should come to the initial equation. (m + 5) * (m-4) m * m = m^2 5 * m = 5m m * -4 = -4m 5 * -4 = -20 So, in combining like terms, you'd get m^2 + 1m -20.
http://www.mathwarehouse.com/algebra/factor/how-to-factor-trinomials-step-by-step.php - This link might help you figure out how to factor. Good luck!
