Answer:
(2)y²
Step-by-step explanation:
2 x y²
This year
2:7
18:?
well 2*9=18
so 7*9=63
18/63
(18+63=total 81 students)
Last year
1/8
multiply by 9
9/72
9 less students this year
Answer:
-7
Step-by-step explanation:
Answer:
-2n²
Step-by-step explanation:
Using the image attached:
We see that the second differences (blue ones) are all equal so we conclude that this is a quadratic sequence.
The quadratic sequence has the form:

To find the value of a we just divide second difference ( -4 ) by 2:
Now we have:
Substitute
and
into the equation above:
Since
= -2 and
= -8 , after simplification we have:
The solution of this system is:
The general term is :
