Respuesta :

Answer:

-2

Step-by-step explanation:

Let's call the number x. The statement tells us that

x^2 - 10 = 3x, or

x^2-3x-10 = 0

Factoring:

(x-5)(x+2) = 0. Here, we see that there are two solutions: x = 5 and x = -2. So, the negative solution is x = -2.