Question

матеметика
5n+1-5n-1/2*5^n

Answer 1

$frac{5^{n+1}-5^{n-1}}{2*5^n}=frac{5^2*5^{n-1}-1*5^{n-1}}{2*5*5^{n-1}}=\\frac{(5^2-1)*5^{n-1}}{2*5*5^{n-1}}=\\frac{25-1}{10}=frac{24}{10}=2.4$