Answer:

where
is the number of laptops, and
is the year.
in 2017: 
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

where
is the number of laptops.
since x is the number of years that have passed since 2007, it can be represented like this:

where
can be any year, so the equation to model the situation using the year:

and this way we can find the number of laptos at the end of 2017:

and


The best batch size is 1053.
Since 5% have failed, this means 95% have passed the test.
95% = 95/100 = 0.95
We can set up an equation to answer this:
0.95x = 1000
Divide both sides by 0.95:
0.95x/0.95 = 1000/0.95
x = 1052.6 ≈ 1053
<h3>
Answer: 96</h3>
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Work Shown:

Answer:
radius is 2.5
volume of ice cream is 58.9 cm cubed
Step-by-step explanation:
to calculate the volume of a cone v=pi x r^2 x (h/3)
v=volume
r=radius
h=height
^ means powers and roots
depth in cones is the same as height
v=3.14 x 2.5^2 x (9/3)
order of operations
v=3.14 x 2.5^2 x 3
v=3.14 x 6.25 x 3
v=19.625 x 3
v=58.875
round
v=58.9
this gives
total area of the field = 4655 sqyrd + 1884.79 sqyrd = 6539.79 sqyrd
cost of fertilising 1 sqyrd = $ 0.08
so cost of fertilising 6539.79 sqyrd = 6539.79 * $ 0.08 = $ 523.18