Answer:
1598.2
Step-by-step explanation:
I used a calculator on this one.
Answer:
The first term is:
Step-by-step explanation:
The arithmetic sequence is defined by
where
is the first term
is the common difference
as
the 17th term of an arithmetic sequence is 51.
i.e. 
so
∵ 
, , 
∵ 
Therefore, the first term is:
You have the correct axis of symmetry value. Nice work.
Plug that x value into the equation to get...
y = -2x^2 - 12x - 10
y = -2*(-3)^2 - 12*(-3) - 10 <<-- replace every x with -3; then use PEMDAS
y = -2*(9) - 12*(-3) - 10
y = -18 + 36 - 10
y = 18 - 10
y = 8
The vertex is the ordered pair (-3, 8)
Note: the axis of symmetry is the vertical line through the vertex
