>but come high school it could be worse to have lower grades in more challenging courses, depending on how hard the GPA hit is.
At least when I was in high school, the regular, pre-AP and the AP classes each had a different grade scale. Core classes were a 1.0(70%)-4.0(100%), pre-AP were +1 (1-5) and AP were +2 (2-6). So in theory they were taking into account how difficult the classes were. Since this was in the DFW area, I'd expect something similar in Dallas.
At least when I was in high school, the regular, pre-AP and the AP classes each had a different grade scale. Core classes were a 1.0(70%)-4.0(100%), pre-AP were +1 (1-5) and AP were +2 (2-6). So in theory they were taking into account how difficult the classes were. Since this was in the DFW area, I'd expect something similar in Dallas.