Odpowiedź :
[tex]a_1 = x - 1 \\ a_2 = 4 \\ a_3 = 8[/tex]
[tex]a_2 + r = a_3 \\ 4 + r = 8 \\ r = 4[/tex]
[tex]a_1 + r = a_2 \\ x - 1 + 4 = 4 \\ x - 1 = 0 \\ \boxed{x = 1}[/tex]
[tex]a_1 = x - 1 \\ a_2 = 4 \\ a_3 = 8[/tex]
[tex]a_2 + r = a_3 \\ 4 + r = 8 \\ r = 4[/tex]
[tex]a_1 + r = a_2 \\ x - 1 + 4 = 4 \\ x - 1 = 0 \\ \boxed{x = 1}[/tex]