Question

(|x| - 3) (|y| + 4) = 12. How many pairs of integers (x, y) satisfy this equation?

1. 4
2. 10
3. 6
4. 8

Explanatory Answer

Product of two integers is 12. Further |y| + 4 ±4. So, we know that one of the numbers has to be greater than 4.

So, we can have
1 x 12 => x = ±4, y = +8
2 x 6 => x = ±5, y = +2
3 x 4 => x = ±6, y = 0
4 + 4 + 2 = 10 possible solutions

Answer Choice (B)