What two numbers multiply to -409 and add up to 408?

Here we answer the question: "What two numbers multiply to -409 and add up to 408?"

The answer to your question is:

-1 and 409

Below we illustrate and prove that -1 and 409 multiply to -409 and add up to 408:

-1 × 409 = -409
-1 + 409 = 408

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

x² + 408x - 409 = 0

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

(x - 1 ) (x + 409)

To summarize, since -1 and 409 multiply to -409 and add up 408, you know that the following is true:

x² + 408x - 409 = (x - 1 ) (x + 409)

Multiply To One Number and Add Up To Another
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