<em>Hi there!</em>
<em>~</em>
<em></em>
<em></em>
<em>Distribute the Negative Sign:</em>
<em></em>
<em></em>
<em>Combine Like Terms:</em>
<em></em>
<em></em>
<em>Answer : </em>
<em></em>
<em>Hope this helped you!</em>
Explicit Formula
Just in case you don't know what this is, the explicit formula is the formula that solves for any term in the series without necessarily knowing what came before the term you are solving.
<em><u>Givens</u></em>
d = t_(n + 1) - t_n You can take any term and the next term for this part of the formula
d = t_3 - t_2
t_3 = 1
t_2 = -7
d = 1 - - 7 = 8
a = -15
<em><u>Formula</u></em>
t_n = a + (n - 1)*d
t_n = -15 + (n - 1)*8
For example find the 5th term.
t_5 = - 15 + (5 - 1)*8
t_5 = - 15 + 4 *8
t_5 = -15 + 32
t_5 = 17 Which is what you have.
Recursive Formula
Computers really like this formula. They use it in what is called a subroutine and they pass values from one part of the program to a subroutine which evaluates the given and sends the result back. I'm telling you all this so you see why you are doing it. The disadvantage of it for humans is that you must know the preceding term to use the recursive formula.
<em><u>Formula</u></em>
t_n = t_(n - 1) + d
<em><u>Example</u></em>
t_6 = t_(6 - 1) + d
t_6 = t_5 + 8
t_6 = 17 + 8
t_6 = 25
You can check this by using the explicit formula.
For this case we have the following expressions:
70,000,000
7,000,000
If we divide the first expression by the second we have:

Thus, we have that the first expression is 10 times greater than the second expression.
Answer:
70,000,000 is 10 times greater than 7,000,000
You can multiply 16 times what equls 88 and then divide by 4 much more simple than it sounds and also your in high school and u cant solve this problem