A parabola opening up or down has vertex (0,0) and passes through (–8,8). Write its equation in vertex form.

Alex drew a circle with right triangle prq inscribed in it, as shown below: the figure shows a circle with points p, q, and r on it forming an inscribed triangle. side pq is a chord through the center and angle r is a right angle. arc qr measures 80 degrees.

Solve for x and y: 217x + 131y = 913; 131x + 217y = 827

Select the margin of error that corresponds to the sample mean that corresponds to each population: a population mean of 360, a standard deviation of 4, and a margin of error of 2.5%