Equation B is written in vertex form, which means you can read the vertex (extreme value) from the numbers in the equation.
Vertex form is
y = a(x -h)² + k
where the vertex (extreme point) is (h, k). Whether that is a maximum or a minimum depends on the sign of "a". When "a" is negative, the graph is a parabola that opens downward, so the vertex is a maximum.
Equation B reveals its extreme value without needing to be altered.
The extreme value of this equation is a maximum at the point (2, 5).
