Select all of the following that are quadratic equations.
5x2+ 15 x=0
6 *- 1 = 4 x + 7
x2.4 x= 4 x + 7
02x-1=0
3x2 + 5 x 7=0
03. 2x2 + 1 = 0

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.

Ican’t i can’t do it