Question

помогите пожалуйста

Answer 1

$\displaystyle\bf\\\\\\0+\frac{1}{2} =\frac{1}{2} \\\\\\\frac{1}{2} +\frac{1}{2} =1\\\\\\1+\frac{1}{2} =\frac{3}{2} \\\\\\\frac{3}{2} +\frac{1}{2} =2\\\\\\2+\frac{1}{2} =\frac{5}{2} \\\\\\\frac{5}{2} +\frac{1}{2} =3\\\\\\Otvet \ : \ 3\\\\2)\\\\a_{n} =\frac{n-3}{n+1} \\\\\\a_{15} =\frac{15-3}{15+1} =\frac{12}{16} =\frac{3}{4} =0,75\\\\\\Otvet \ : \ a_{15} =0,75$