That would be expressed algebraically as
 
 
        
        
        
<u>c) 3, 6, 9 12</u>  is NOT a geometric progression
<h3>Further explanation
</h3>
Geometry sequences are series of numbers that have a constant ratio
or can be interpreted:
Each number is obtained by multiplying the previous number by a constant
The sequence can be:
a, ar, ar², ar³, ... etc.
Can be formulated
 
where:
a is the first term, and
r is the common ratio
So we have to see the series has the same ratio or not
a. 
b. 
c.
d. 
<h3>Learn more
</h3>
a geometric sequence
brainly.com/question/1480821
Determine whether the sequence below is a geometric
brainly.com/question/978528
the formula for a finite geometric series
brainly.com/question/4520322
Keywords : a geometric sequence, the first term, the common ratio
 
        
                    
             
        
        
        
Answer: x is grater or equal to -18
Inter el notation
[-18,oo)
Step-by-step explanation:
 
        
             
        
        
        
Answer:
61 bags of lettuce
Step-by-step explanation:
Let's create two equations representing the cost of bags of lettuce:
Val's Veggies: 250 + 1.50x = V
Sally's Salads: 100 + 4.00x = S
If you buy 60 bags of lettuce from either store, the answers will be equivalent:
If x = 60
250 + 1.50x = V
250 + 90 = V
340 = V
100 + 4.00x = S
100 + 240 = S
340 = S
Now that both equations are equivalent, all we need to do to tip the balance and make Val's Veggies cheaper is purchase one more bag of lettuce:
x = 61
250 + 1.50x = V
250 + 91.50 = V
341.50 = V
100 + 4.00x = S
100 + 244 = S
344 = S
Since V represents the price of a bag of lettuce at Val's Veggies and V is now less than S (Sally's Salads), Val's Veggies is now the cheaper option. 
Therefore, 61 bags of lettuce must be purchased in order for Val's Veggies to be the cheaper option.