Here we answer the question: "What two numbers multiply to -72 and add up to -21?"
The answer to your question is:
-24 and 3
Below we illustrate and prove that -24 and 3 multiply to -72 and add up to -21:
-24 × 3 = -72
-24 + 3 = -21
Are you asking because you are trying to figure out how to factor the following quadratic equation?
x2 - 21x - 72 = 0
If so, the solution to factor the quadratic equation above is:
(x - 24 ) (x + 3)
To summarize, since -24 and 3 multiply to -72 and add up -21, you know that the following is true:
x2 - 21x - 72 = (x - 24 ) (x + 3)
Multiply To One Number and Add Up To Another
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