Question

F (k)= 5^k
Найти F (k+2) - F (k+1)

Answer 1

F(k)=5^k
F(k+2)-F(k+1)=5^(k+2)-5^(k+1)=

5^((k+1)+1)-5^(k+1)=

5*5^(k+1)-5^(k+1)=5^(k+1) •(5-1)=

4*5^(k+1)

Answer 2

спасибо