What two numbers multiply to -641 and add up to -640?

Here we answer the question: "What two numbers multiply to -641 and add up to -640?"

The answer to your question is:

-641 and 1

Below we illustrate and prove that -641 and 1 multiply to -641 and add up to -640:

-641 × 1 = -641
-641 + 1 = -640

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

x² - 640x - 641 = 0

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

(x - 641 ) (x + 1)

To summarize, since -641 and 1 multiply to -641 and add up -640, you know that the following is true:

x² - 640x - 641 = (x - 641 ) (x + 1)

Multiply To One Number and Add Up To Another
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