Find the number of ordered pairs $(a,b)$ of integers such that \frac{a + 2}{a + 1} = \frac{b}{8}.
(a + 2) /(a + 1) = b / 8
8(a + 2) / (a + 1) = b
a b
0 16
1 12
3 10
7 9
-2 0
-3 4
-5 6
-9 7
+355 
