Odpowiedź:
[tex] {x}^{2} - 4 = 0 \\ {x}^{2} = 4 \\ x_{1} = 2 \\ x_{2} = - 2 \\ \\ {x}^{2} - 1 = 0 \\ {x}^{2} = 1 \\ x_{3} = 1 \\ x_{4} = - 1[/tex]
średnia arytmetyczna
[tex] \frac{2 + ( - 2) + 1 + ( - 1)}{4} = \frac{2 - 2 + 1 - 1}{4} = \frac{0}{4} = 0[/tex]
B.