Three vertices of a rectangle are given. find the coordinates of the fourth vertex.

(–3, –3), (7, –3), (7, 2)

So we can get pairs
(x,y)
we have
(-3,-3)
(7,-3)
(7,2)

so list known ones
x=-3,7,7
y=-3,-3,2
we find pairs
x=7 and 7
y=-3 and -3
the missing one is another -3 for x and 2 for y
therefor the last point is
(-3,2)

If i think this is what your asking, he should look at the grams or pounds/ounces and compare the to their cost then max can identify which one is proportional and which is not ( i think xd)

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.