Respuesta :

Answer:

9,-10

Step-by-step explanation:

Let u be a number.

[tex]u + {u}^{2} = 90[/tex]

[tex]u {}^{2} + u - 90 = 0[/tex]

[tex](u + 10)(u - 9) = 0[/tex]

[tex]u = - 10[/tex]

or

[tex]u = 9[/tex]

9, -10
9,-10 the guy above got what I got