Answer:
<h2>a = 11</h2>
Step-by-step explanation:

To find if a series is either geometric or arithmetic:
it must satisfy this property:
Arithmetic:
a(n+1) - a(n) = const
Geometric:
a(n+1)/a(n) = const
In your case:
r1 = 7 -4 = 3
r2 = 12 - 7 = 5
r1 != r2 (not arirthmetic)
Geometric check:
r1 = 7/4
r2 = 12/7
r1 != r2 (not Geometric)
so neither.
The value of -7² is less than zero which is the correct answer would be an option (D)
<h3>What is the fraction?</h3>
A fraction is defined as a numerical representation of a part of a whole that represents a rational number.
<h3>What are Arithmetic operations?</h3>
Arithmetic operations can also be specified by subtracting, dividing, and multiplying built-in functions.
* Multiplication operation: Multiplies values on either side of the operator
For example 4*2 = 8
To determine the value is less than zero
Option A: (-6)² ⇒ 36
So this value is greater than zero
Option B: 1/3 × 2 ⇒ 2/3
So this value is greater than zero
Option C: 0.5² ⇒ 0.25
So this value is greater than zero
Option D: -7² ⇒ -49
So this value is less than zero
Learn more about the fraction here:
brainly.com/question/10708469
#SPJ1
680 is the answer to that question