Question

(bn): b1+b3=17,b2+b4=68.Знайти S1

Answer 1

b1+b3=17,

b2+b4=68

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b1 + b1*q^2 = 17

b1q + b1*q^3 = q*(b1 + b1*q^2) = q*17 = 68

q = 4

b1 + b1*16 = 17

b1 = 1

S1 = b1 = 1