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:

-8 and 80

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

-8 × 80 = -640
-8 + 80 = 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 - 8 ) (x + 80)

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

x² + 72x - 640 = (x - 8 ) (x + 80)

Multiply To One Number and Add Up To Another
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