Answer:
The common difference (or common ratio) = 0.75
Step-by-step explanation:
i) let the first term be
= 80
ii) let the second term be
=
. r = 80 × r = 60 ∴ r =
= 0.75
iii) let the third term be
=
. r = 60 × r = 45 ∴ r =
= 0.75
iv) let the fourth term be
=
. r = 45 × r = 33.75 ∴ r =
= 0.75
Therefore we can see that the series of numbers are part of a geometric progression and the first term is 80 and the common ratio = 0.75.

the equation is a quadratic one, and it has a positive coefficient on the leading term, meaning, is opening upwards, so it has a "burrow" for the vertex.
the minimum or lowest point for a quadratic opening upwards is, well, the vertex point :), the "x" value is the year, the "y" or f(x) value is the population, we're asked for the year, or the x-coordinate of the vertex
well
6 can only go into 6 once
Answer:
31
Step-by-step explanation:
210 ft ÷ 7 ft = 30
There are 30 7-ft lengths of fence.
Think of putting a post at the end of each 7-ft length. That means you need 30 posts. Now you must add 1 post for the beginning.
Answer: 31