Final answer:
The slope of line b is -1/m. The slope of line c is -1/m.
Step-by-step explanation:
The slope of line a is m. Since lines a and b are perpendicular, the product of their slopes is -1. Therefore, the slope of line b is -1/m.
Since lines b and c are perpendicular, the product of their slopes is -1. Therefore, the slope of line c is -1/m.