Either if the shape have 3 sides or all the angles add up to 180 degrees
Answer:
81
Step-by-step explanation:
the formula for an arithmetic sequence:
aₙ = a₁ + (n-1)d
where aₙ = the nth term
a₁ = the 1st term = -3
n = the term number = 13
d = the common difference = 7
Plugging in those values into the formula to find a₁₃:
a₁₃ = -3 + (13-1)7
= -3 + (12)7
= -3 + 84
= 81
To find an equation to describe the relationship between t and c you:
1. Find what is the dependent variable and the independent variable
In this case the total cost of the tickets depend of the number of tickets. Then:
Dependent variable is C
Independent variable is T
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You can see in the table that the difference between the cost of the tickects is 165 for every 3 tickets. you find this by substracting the data in every column, as follow:
Then, the equation will be a lineal equation with a slope of:

You use a point of the lineal relationship to find the equation:
(2,110) t1=2 c1= 110
You use the next formula:

You replace the coordinates of the point and find the value of b:


The equation is:
The answer is 144 over 13