What two numbers multiply to 81 and add up to -18?

Here we answer the question: "What two numbers multiply to 81 and add up to -18?"

The answer to your question is:

-9 and -9

Below we illustrate and prove that -9 and -9 multiply to 81 and add up to -18:

-9 × -9 = 81
-9 + -9 = -18

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

x² - 18x + 81 = 0

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

(x - 9 ) (x - 9)

To summarize, since -9 and -9 multiply to 81 and add up -18, you know that the following is true:

x² - 18x + 81 = (x - 9 ) (x - 9)

Multiply To One Number and Add Up To Another
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