The vertex is a minimum point. The y value of the vertex is the lowest point it hits. The graph is going down, the vertex is the lowest point of it
124 - 78 = 46.....Harrison used 46 more blocks then Greyson
The art sculpture was 70 inches aka 5.9feet tall and if we round it well it would be 6feet so that would be its highest piont
If "a" and "b" are two values of x-coordinate, and "m" is the midpoint between them, it means the distance from one end to the midpoint is the same as the distance from the midpoint to the other end
... a-m = m-b
When we add m+b to this equation, we get
... a+b = 2m
Solving for m gives
... m = (a+b)/2
This applies to y-coordinates as well. So ...
... The midpoint between (x1, y1) and (x2, y2) is ((x1+x2)/2, (y1+y2)/2)
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Jennifer had (x1, y1) = (-4, 10) and (x2, y2) = (-2, 6). So her calculation would be
... midpoint = ((-4-2)/2, (10+6)/2) = (-6/2, 16/2) = (-3, 8)
Brandon had (x1, y1) = (9, -4) and (x2, y2) = (-12, 8). So his calculation would be
... midpoint = ((9-12)/2, (-4+8)/2) = (-3/2, 4/2) = (-1.5, 2)