Write an equation in standard form for a hyperbola centered at (0, 0) with a focus at (0, 6) and a constant difference of 8.

Describe the 2 algebraic methods you can use to find the zeros of the function f(t)=-16t^2+400.

Set $r$ is a set of rectangles such that (1) only the grid points shown here are used as vertices, (2) all sides are vertical or horizontal and (3) no two rectangles in the set are congruent. if $r$ contains the maximum possible number of rectangles given these conditions, what fraction of the rectangles in set $r$ are squares? express your answer as a common fraction.

What is the value of x? enter your answer in the box.