Answer:
![l=31+20(y-2007)](https://tex.z-dn.net/?f=l%3D31%2B20%28y-2007%29)
where
is the number of laptops, and
is the year.
in 2017: ![l=231](https://tex.z-dn.net/?f=l%3D231)
Step-by-step explanation:
I will define the variable
as the number of years that passed since 2007.
Since the school buys 20 lapts each year, after a number
of years, the school will have
more laptops.
and thus, since the school starts with 31 laptops, the equation to model this situation is
![l=31+20*x](https://tex.z-dn.net/?f=l%3D31%2B20%2Ax)
where
is the number of laptops.
since x is the number of years that have passed since 2007, it can be represented like this:
![x=y-2007](https://tex.z-dn.net/?f=x%3Dy-2007)
where
can be any year, so the equation to model the situation using the year:
![l=31+20(y-2007)](https://tex.z-dn.net/?f=l%3D31%2B20%28y-2007%29)
and this way we can find the number of laptos at the end of 2017:
![y=2017](https://tex.z-dn.net/?f=y%3D2017)
and
![l=31+20(y-2007)](https://tex.z-dn.net/?f=l%3D31%2B20%28y-2007%29)
![l=31+20(2017-2007)\\l=31+20(10)\\l=31+200\\l=231](https://tex.z-dn.net/?f=l%3D31%2B20%282017-2007%29%5C%5Cl%3D31%2B20%2810%29%5C%5Cl%3D31%2B200%5C%5Cl%3D231)
Answer:
see below
Step-by-step explanation:
sqrt(90)
We know that sqrt(ab) = sqrt(a) sqrt(b)
sqrt(9*10)
sqrt(9) sqrt(10)
3*sqrt(10)
i’m pretty sure the answer is 3
21 divided by 7 equals 3
-the equation is a quadratic
-the axis of symmetry is x=-7
-the graph has a relative maximum