Answer:
The Basic Identities are :



So for this question :




She would place it before the 4.
13) b=145 because a line equals 180° so you subtract 35° from 180°
14) b=61 because it as right angle so 90 minus 29 equals 61
15) b= 23 because 360 is a full circle so you add 243 and 94 and get 337 then subtract 337 from 360
16)b=131 because you subtract 49 from 180
17) b=90 because you subtract 90 from 180
18) b=73 because of vertical angles
As we already have the model that describes the change of the population in Italy in terms of the years that have elapsed, we only have to replace the conditions that are requested in that equation.
Therefore to find the population of Italy in the year 2000 (t = 10 years) substitute t = 10 in the equation and have:

million people
To find the population of Italy in 2008 (t = 18 years)
substitute t = 18 in the equation and have:

million people
To predict the population in Italy for 2015 and 2020 with this model, we substitute in the equation t = 25 and t = 30
t = 25
million people
t = 30
million people
The discriminant is

which is 0.
Since the discriminant is 0, there is only one real solution.