These are pretty easy once you get the concept.
think of <em>random letter</em> (x) as the term y, so in the case of p(x)=-3+4x, its just asking what is y when x equals all those values.
so p(-2) = -3 + 4(-2), since its asking to plug in -2 for x, which equals -11
p(0) = -3 + 4(0)
= -3
p(5) = -3 + 4(5)
= 17
In this case, i think you just need to divide the amount of telephone subscription and divide it among 100 people
For example, let's say that there is around 2,000,000 subscription for 100,000 users.
The amount would be : 2,000,000 / 1,000
= 2,000 number of mobile per 100 people
hope this helps
Because pools are normally very large, you would use a larger unit, like meters, to measure it. Fish tanks are usually a lot smaller than pools, so you would use a smaller unit to measure them, like centimeters.
Your answer is a fish tank.