Question 167560
The number of people infected after t days is P = 200 + 5t - t2. Find the number of days until the number of people infected is 176. 

solution:

Let the number of people infected afetr t days be P

P = 200 + 5t - t^2

we haev to find t when P = 176

we have to solve for t 
200+ 5t - t^2 = 176
t^2-5t-24=0
t^2-8t+3t-24=0
(t-3)(t-8)=0
Hence t=3 or t=8