Question

ПОЖАЛУЙСТАА!!..............​

Answer 1

$b_{1}=8\\\\q=\frac{1}{2} \\\\S_{5} =\frac{b_{1}(1-q^{5})}{1-q}=\frac{8*[1-(\frac{1}{2})^{5}]}{1-\frac{1}{2} }=\frac{8*(1-\frac{1}{32}) }{\frac{1}{2}}=16*\frac{31}{32}=\frac{31}{2}=15,5\\\\\boxed{S_{5} =15,5}$