Find the equation of the circle in standard form for the given center (h, k) and radius r: (h, k) = (5, 4), r = 2
(x − 5)2 + (y − 4)2 = 4(x + 5)2 + (y + 4)2 = 2(x + 5)2 + (y + 4)2 = 4(x − 5)2 + (y − 4)2 = 2

Twenty-five percent of the customers entering a grocery store between 5 p.m. and 7 p.m. use an express checkout. consider five randomly selected customers, and let x denote the number among the five who use the express checkout.

The graph shows the distance y, in inches, a pendulum moves to the right (positive displacement) and to the left (negative displacement), for a given number of seconds x. how many seconds are required for the pendulum to move from its resting position and return? enter your answer in the box.

Atrain leaves little? rock, arkansas, and travels north at 90 kilometers per hour. another train leaves at the same time and travels south at 80 kilometers per hour. how long will it take before they are 680 kilometers? apart?