A student makes a model rocket using a soda bottle. When launched, the rocket's height, in feet, is given by the function h(d) = -(d-9)2 + 81,
where d represents the distance the rocket is from the launch pad.
What is the height of the rocket when it is 15 feet from the launch pad,
represented by h(15)?

2people are trying different phones to see which one has the better talk time. chatlong has an average of 18 hours with a standard deviation of 2 hours and talk-a-lot has an average of 20 hours with a standard deviation of 3. the two people who tested their phones both got 20 hours of use on their phones. for the z-scores i got 1 for the chatlong company and 0 for talk-a-lot. what is the percentile for each z-score?

Find the domain of the following expression: 1/(√x)-2

Factor the expression using gcf 9b+45