PLEASE HALP ME PEOPLE I NEED HALP

(98 points) i need with 5 questions. answer definitions are welcomed, but not necessary.

You are on a cycling trip around europe with friends. you check the weather forecast for the first week. these are the temperatures for the week. sun mon tues wed thurs fri sat 16°c 20°c 24°c 28°c 28°c 23°c 15°c what is the mean temperature forecast for the week?

What is the axis of symmetry of the function f(x)=-(x+ 9)(x-21)