Part 1
The best equation that represents the situation described is:
y = -0.75x + 3
This is because the ice thickness decreases over time, so the slope should be negative (indicating a decrease). The initial thickness of the ice was 3 meters, which is represented by the y-intercept.
Part 2
The slope in this situation is -0.75 and represents the decrease in ice thickness (in meters) per week.
The y-intercept in this situation is 3 and represents the initial thickness of the ice (3 meters) at the beginning of spring (when x = 0).