Please help me!
It is timed!
I will give brainliest!

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

Will mark the brainliest.paula makes stained-glass windows and sells them to boutique stores. if her costs total $12,000 per year plus $4 per window for the frame. how many windows must she produce to earn a profit of at least $48,000 in one year if she sells the windows for $28 each?

In a tutoring session, 2/3 of an hour was spent reviewing math problems. adelina attended 3/4 of the tutoring session. how much time did adelina spend at the tutoring session?