Question

Am nevoie de rezolvare la ex8 16 si 17

Answer 1

8.

$\it b_5=3\ \ \ \ \ (*)\\ \\ b_7=27 \Rightarrow b_5+2r=27\ \stackrel{(*)}{\Longrightarrow}\ 3+2r=27\bigg|_{-3} \Rightarrow 2r=24\bigg|_{:2} \Rightarrow\ r=12\\ \\ \\ b_{15}=b_7+8r=27+8\cdot12=27+96=123$