What two numbers multiply to -90 and add up to 9?

Here we answer the question: "What two numbers multiply to -90 and add up to 9?"

The answer to your question is:

-6 and 15

Below we illustrate and prove that -6 and 15 multiply to -90 and add up to 9:

-6 × 15 = -90
-6 + 15 = 9

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

x² + 9x - 90 = 0

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

(x - 6 ) (x + 15)

To summarize, since -6 and 15 multiply to -90 and add up 9, you know that the following is true:

x² + 9x - 90 = (x - 6 ) (x + 15)

Multiply To One Number and Add Up To Another
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