need help understanding

1. Find an equation describing the points P = (*>) which are equidistant from Q = (2,3) and R = (5,-1). 2. Fig. 9 shows the temperature of a cup of coffee during a ten-minute period. (Each of your answers in (a) - (c) should have the units "degrees per minute.") a. What was the average rate of cooling from minute 0 to minute 10? What was the average rate of cooling from minute 7 to minute S? from minute $ to minute 9? c. What was the rate of cooling at minute $? at minute 2? 130% Temperature of a cup of coffee Temperature ( OF ) 100- 70 Time (minutes) Fig- 9 3. Let P = (1, -2) and Q = (5, 4). Find: (a) the midpoint R of the line segment PQ. (b) the point T that is 1/3 of the way from P to Q: (c) the point S that is 2/5 of the way from P to Q. 4. Find an equation for each line. (a) LI goes through the point (2, 5) and is parallel to 3x - 2y = 9. (b) 12 goes through the point (-1, 2) and is perpendicular to 2x = 7 - 3y. 5. Find the slope of the line through the points P and O when: (a) P (2, -3) and Q (2 + h, 1 - (1 + h)) (b) P (x, x-) and Q (xth,x2 +2xh + h ) (c) P (x, x ) and Q (x - h, x- - 2xh th- )