Jack and Jill are hiking on a mountain. Jack's hike is modeled by the linear equation d=0.7t+3 and Jill's hike is modeled by the linear equation d=−0.7t+3, where d is the distance, in miles, from the base of the mountain and t is the time, in hours, since the start of the hike. a. What is Jill's rate of change?

b. What does this rate tell you about her direction of movement?

(will give brainliest)