Question

Quero a resoluçao desse calculo.
=15
Cx,2

Answer 1

x(x-1) : 2 = 15
x^2-x = 15*2
x^2-x = 30
x^2-x -30= 0

Colocando na formula de baskara:
1 - 4*1*(-30)
1 + 120
121

x' = 1 + 11 : 2 = 6
x'' = 1 - 11 : 2 = - 5

{6}