\[\boxed{\text{8}\text{6}\text{\ (86).\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[1)\ \frac{4a - b}{a} = \frac{4a}{a} - \frac{b}{a} = 4 - \frac{b}{a}\]
\[2)\ \frac{b^{2} + 7b + 3}{b + 7} = \frac{b^{2} + 7b}{b + 7} +\]
\[+ \frac{3}{b + 7} = \frac{b(b + 7)}{(b + 7)} + \frac{3}{b + 7} =\]
\[= b + \frac{3}{b + 7}\]