Find the indicated rate. 15. Given y = pq, find dp/ dt when p = 30, q = 250, 1. Given y = x', find dy/ dt when x = 2 and dx/dt = -4. dq/dt = -200, and dy/ dt = -5250. 2. Given y = x*, find dy/dt when x = 3 and dx/dt = 1.5. 16. Given y = pq, find dq/ dt when p = 150, q = 75, 3. Given y = 2x2 + x, find dy/dt when x = -3 and dp/dt = 60, and dy / dt = 7500. dx / dt = 2. 17. Given y = p-q, find dq/dt when p = 15, q = 40, 4. Given y = -3x- + 2x, find dy/dt when x = -2 and dp/dt = 55, and dy / dt = 54,750. dx / dt = 6. 5. Given y = 2x', find dx/ dt when x = 1 and dy/ dt = 10. 18. Given y = pq , find dp/ dt when p = 80, q = 135, dq/dt = -5, and dy/ dt = 7,654,500. 6. Given y = 4x2, find dx/dt when x = 5 and dy/dt = -3