I need help with 1 please

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

The four students in the table below each recorded the time and distance traveled while exercising. exercising distance (miles) time (minutes) gia 2 30 harris 5 50 ian 3 40 jackson 4 80 which list ranks the students from fastest walker to slowest walker? jackson, gia, ian, harris harris, jackson, ian, gia harris, ian, gia, jackson jackson, harris, ian, gia

Ms. green tells you that a right triangle has a hypotenuse if 13 and a leg of 5. she ask you to find the other leg of the triangle. what is you're answer?