Rob and Wilbur are selling fruit for a school fundraiser. Customers can buy small boxes of grapefruit and large boxes of grapefruit. Rob sold 12 small boxes of grapefruit and 7 large boxes
of grapefruit for a total of $296. Wilbur sold 6 small boxes of grapefruit and 14 large boxes of
grapefruit for a total of $358. Find the cost each of one small box of grapefruit and one large box
of grapefruit

First locate the turning point (vertex) of the graph. which is at the coordinates x=5 and y=9 or (5; 9).to determine whether it's a maximum or mininum value, you have to discern whether the vertex's y-value is the highest value or lowest value the graph can reach. since the vertex's y-value, 9 is the highest value the graph can reach, it will be a maximum.another basic way to determine whether the vertex's value is max or min is to see if the graph is smiling or sad. if it's smiling, the turning point/vertex would be a minimum, while a sad parabola would have a maximum y-value at the vertex.