The results for the ordered pairs are:
- \((10, -7)\) is a solution: \(\text{True}\)
- \((-11, -12)\) is a solution: \(\text{False}\)
- \((7.5, -7.5)\) is a solution: \(\text{True}\)
Thus, the final answers are:
\[
\boxed{(10, -7) \text{ is a solution}, (-11, -12) \text{ is not a solution}, (7.5, -7.5) \text{ is a solution}}
\]