Addition, Subtraction, Multiplication, and Division involving Negative Numbers

Given that \(p\) and \(q\) are integers such that \(-10 \leq p < 2\) and \(0 \leq q < 7\), find

1. the greatest possible value of \(p + q\),
2. the greatest possible value of \(q - p\),
3. the smallest possible value of \(pq\),
4. the greatest possible value of \(pq\),
5. the smallest possible value of \(p^2 + q^2\),
6. the greatest possible value of \(p^2 + q^2\).