What two numbers multiply to 639 and add up to 80?

Here we answer the question: "What two numbers multiply to 639 and add up to 80?"

The answer to your question is:

9 and 71

Below we illustrate and prove that 9 and 71 multiply to 639 and add up to 80:

9 × 71 = 639
9 + 71 = 80

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

x² + 80x + 639 = 0

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

(x + 9 ) (x + 71)

To summarize, since 9 and 71 multiply to 639 and add up 80, you know that the following is true:

x² + 80x + 639 = (x + 9 ) (x + 71)

Multiply To One Number and Add Up To Another
Did you find the information on this page useful? Here you can solve a similar problem.