What multiply 30 and add to - 17

-15 and - 2 because two negatives equal a positive

-3 x 10 = - 30

-3 + (10) = 7

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

x2 + 7x - 30 = 0

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

(X - 3) (X + 10)

To summarize, since - 3 and 10 multiply to - 30 and add up 7, you know that the following is true:

x2 + 7x - 30 = (X - 3) (X + 10)