Find the value of the variable. then find the measure of each labeled angle

What is the value of the expression 9+n/3-6 when n = 12? 1. 5. 7. 12.

David is spreading mulch on a triangular area of his flower bed. the coordinates of the vertices of the area are (1, 3), (9, 3), and (4, 6). what is the area of the triangle if each square has an area of 3 square feet?

These tables represent a quadratic function with a vertex at (0, -1). what is the average rate of change for the interval from x = 9 to x = 10?