+1439 Find the number of ordered pairs $(a,b)$ of integers such that
\frac{a + 2}{a + 1} = \frac{b}{8}.
+129847 (a + 2) / ( a + 1) = b / 9
8 (a + 2) = b ( a + 1)
8a + 16 = ab + b
ab + b - 8a = 16 multiply the coefficients on a,b and add to both sides
ab + b - 8a - 8 = 16 - 8
(a + 1) ( b - 8) = 8
Factors of 8 a b
4, 2 3 10
2, 4 1 12
1, 8 0 16
8. 1 7 9
-4 , -2 -5 6
-2, - 4 -3 4
-1, -8 -2 0
-8. -1 -9 7
