What two numbers multiply to -391 and add up to 390?

Here we answer the question: "What two numbers multiply to -391 and add up to 390?"

The answer to your question is:

-1 and 391

Below we illustrate and prove that -1 and 391 multiply to -391 and add up to 390:

-1 × 391 = -391
-1 + 391 = 390

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

x² + 390x - 391 = 0

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

(x - 1 ) (x + 391)

To summarize, since -1 and 391 multiply to -391 and add up 390, you know that the following is true:

x² + 390x - 391 = (x - 1 ) (x + 391)

Multiply To One Number and Add Up To Another
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