Which equation represents the line shown on the graph?

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

(b) suppose that consolidated power decides to use a level of significance of α = .05, and suppose a random sample of 100 temperature readings is obtained. if the sample mean of the 100 temperature readings is x⎯⎯ = 60.990, test h0 versus ha and determine whether the power plant should be shut down and the cooling system repaired. perform the hypothesis test by using a critical value and a p-value. assume σ = 5. (round your z to 2 decimal places and p-value to 4 decimal places.)

An elevator travels 310 feet in 10 seconds. at that speed, how far can't his elevator travel in 12 seconds?