Rachel hikes at a steady rate from a ranger station to a campground that is 20 mi away. after 2 h, she is 13 mi from the campground. after 4 h, she is 6 mi from the campground. a graph shows her distance from the campground y, in miles, after x hours. what is the slope of the graph, and what does it represent? ( explain how you solved the problem) 

The slope is 3.5. it represents the fact that she hikes 3.5 miles per hour. i figured this our because after 2 hrs of hiking she turned 20 miles into 13. the difference between those is 7. that's for two hours of hiking, so divide by 2 and get 3.5, which is the rate of change per hour. you can do the same thing by subtracting 6 from 13 and dividing the answer by 2. you get the same answer, so you can for sure say she hikes 3.5 miles per hour. the slope would be 3.5 over 1, or 3.5. hope this and makes sense!

Ithink if im not mistaking b is -3 but im not a 100% sude