Respuesta :
Given [tex]a_7=125[/tex] you can find a_6:
[tex]a_6= \frac{125-3}{2} =61[/tex]
[tex]a_5= \frac{61-3}{2} =29 \\ a_4= \frac{29-3}{2}=13 \\ a_3= \frac{13-3}{2} =5 \\ a_2= \frac{5-3}{2} =1 \\ a_1= \frac{1-3}{2}=-1 [/tex]
Answer: -1
[tex]a_6= \frac{125-3}{2} =61[/tex]
[tex]a_5= \frac{61-3}{2} =29 \\ a_4= \frac{29-3}{2}=13 \\ a_3= \frac{13-3}{2} =5 \\ a_2= \frac{5-3}{2} =1 \\ a_1= \frac{1-3}{2}=-1 [/tex]
Answer: -1