+106 The graph of $y=ax^2+bx+c$ is shown below. Find abc. (The distance between the grid lines is one unit.)
+179 Since the graph passes through (-3, -2), (-1, 0), and (-5, 0), we have the equations \(9a-3b+c = -2, a-b+c = 0,\) and \(25a-5b+c= 0\). Solving, we have a = 1/2, b = 3, c = 5/2, which means that abc = 15/4
+36915 Parabola with vertex -3,-2
Vertex form y = a (x+3)^2 - 2 choose point (-1,0) when x = -1 y = 0 shows a = 1/2
y = 1/2 (x+3)^2 -2 expand
y = 1/2 x^2 +3x + 2.5 1/2 x 3 x 2.5 = 3.75 ( as EL found via a different method !)
