What two numbers multiply to -243 and add up to 78?

Here we answer the question: "What two numbers multiply to -243 and add up to 78?"

The answer to your question is:

-3 and 81

Below we illustrate and prove that -3 and 81 multiply to -243 and add up to 78:

-3 × 81 = -243
-3 + 81 = 78

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

x² + 78x - 243 = 0

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

(x - 3 ) (x + 81)

To summarize, since -3 and 81 multiply to -243 and add up 78, you know that the following is true:

x² + 78x - 243 = (x - 3 ) (x + 81)

Multiply To One Number and Add Up To Another
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