What two numbers multiply to -640 and add up to -72?

Here we answer the question: "What two numbers multiply to -640 and add up to -72?"

The answer to your question is:

-80 and 8

Below we illustrate and prove that -80 and 8 multiply to -640 and add up to -72:

-80 × 8 = -640
-80 + 8 = -72

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

x² - 72x - 640 = 0

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

(x - 80 ) (x + 8)

To summarize, since -80 and 8 multiply to -640 and add up -72, you know that the following is true:

x² - 72x - 640 = (x - 80 ) (x + 8)

Multiply To One Number and Add Up To Another
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