Which graph shows the solution set of x^2+4-12x/> 0

What is the average rate of change for this function for the interval from x=2 to x=4 ?

How do i do this activity, is appreciated

Candice uses the function f(t)=t+100−−−−−−√ to model the number of students in her after-school program. the variable t represents days and f(t) represents the number of students. how many days does it take for there to be 15 students in her program? a. 225 days b. 125 days c. 325 days d. 115 days