Question

Ребят решите срочно пожалуйста

Answer 1

$b_{1} = -5, b_{n} = -2* frac{1}{b_{n-1}}, n > 1\b_{n} = b_{1}*q^{n-1}\b_{3} = -2 * frac{1}{b_{2}}\b_{1} * q^{2} = -2 * frac{1}{b_{1} * q}\ b^{2}_{1}*q^{3} = -2\q^{3} = -frac{2}{25}, q =  sqrt[3]{-frac{2}{25}}\b_{3} = b_{1} * q^{2} = -5 * sqrt[3]({-frac{2}{25})^{2}}$