Here we answer the question: "What two numbers multiply to -21 and add up to -20?"
The answer to your question is:
-21 and 1
Below we illustrate and prove that -21 and 1 multiply to -21 and add up to -20:
-21 × 1 = -21
-21 + 1 = -20
Are you asking because you are trying to figure out how to factor the following quadratic equation?
x2 - 20x - 21 = 0
If so, the solution to factor the quadratic equation above is:
(x - 21 ) (x + 1)
To summarize, since -21 and 1 multiply to -21 and add up -20, you know that the following is true:
x2 - 20x - 21 = (x - 21 ) (x + 1)
Multiply To One Number and Add Up To Another
Did you find the information on this page useful? Here you can solve a similar problem.