What two numbers multiply to -640 and add up to -639?

Here we answer the question: "What two numbers multiply to -640 and add up to -639?"

The answer to your question is:

-640 and 1

Below we illustrate and prove that -640 and 1 multiply to -640 and add up to -639:

-640 × 1 = -640
-640 + 1 = -639

Are you asking because you are trying to figure out how to factor the following quadratic equation?

x² - 639x - 640 = 0

If so, the solution to factor the quadratic equation above is:

(x - 640 ) (x + 1)

To summarize, since -640 and 1 multiply to -640 and add up -639, you know that the following is true:

x² - 639x - 640 = (x - 640 ) (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.