What two numbers multiply to -642 and add up to 641?

Here we answer the question: "What two numbers multiply to -642 and add up to 641?"

The answer to your question is:

-1 and 642

Below we illustrate and prove that -1 and 642 multiply to -642 and add up to 641:

-1 × 642 = -642
-1 + 642 = 641

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

x² + 641x - 642 = 0

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

(x - 1 ) (x + 642)

To summarize, since -1 and 642 multiply to -642 and add up 641, you know that the following is true:

x² + 641x - 642 = (x - 1 ) (x + 642)

Multiply To One Number and Add Up To Another
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