Відповіді §.19 - §.20 » §.20 (2.4)

Sn = 254,1. xn = 170,1. q = 3. xn = x1 • qn–1 x1 = x_n/q^(n-1) = 170,1/3^(n-1) (x_1•(q^n- 1))/(q-1) = Sn (x_n (q^n- 1))/(q^(n-1) (q-1)) = Sn (x_n (q^n- 1))/(q^n- q^(n-1) ) = Sn (170,1(3^n- 1))/(3^n- 3^(n-1) ) = 254,1. n = 5.