(a) What is the area of the triangle determined by the lines y = - --- x + 9, y 10x, and the y-axis? 27/7 (b) If b> 0 and m< 0, then the line y = mx + b cuts off a triangle from the first quadrant. Express the area of that triangle in terms of m and b. 2m X (c) The lines y = mx + 5, y = x, and the y-axis form a triangle in the first quadrant. Suppose this triangle has an area of 10 square units. Find m. m = -1/4 Additional Materials Reading