Answer:
[-4,2] or
Step-by-step explanation:
Range is the range of the y-axis.
Although we see that the "line" ends at a specific point, it is neither the highest or lowest y-value.
Our lowest y value is -4, and because it is a line, it is not an open dot resulting in a [, instead of a (.
This same thing happens with highest y-value which happens to be 2.
This is interval notation.
Due to your question, you may be asking for this:
Answer:
see explanation
Step-by-step explanation:
the sum to n terms of an arithmetic sequence is
=
[2a + (n - 1)d ]
where d is the common difference and a is the first term
here d = 9 - 7 = 7 - 5 = 2 and a = 5, hence
=
[(2 × 5) + 2(n - 1) ]
= (10 + 2n - 2)
= (2n + 8)
= n² + 4n
When sum = 165, then
n² + 4n = 165 ← rearrange into standard form
n² + 4n - 165 = 0 ← in standard form
(n + 15)(n - 11) = 0 ← in factored form
equate each factor to zero and solve for n
n + 15 = 0 ⇒ n = - 15
n - 11 = 0 ⇒ n = 11
but n > 0 ⇒ n = 11