<span> let x = # of adult tickets
sold, thus the # of children tickets
= 70-x</span>
<span> 7.5x + 5(70-x) = 450</span>
<span> ^ 7.5x + 350 -5x = 450</span>
<span> ^ 2.5x = 450-350= 100</span>
<span> x = 40 adults
tickets thus
70—40 = 30 children tickets</span>
The common difference is 19-7 = 31-19 = 12, so this is an arithmetic sequence. The initial term (when n=1) is 7.
The explicit formula for the terms of an arithmetic sequence is
an = a1 + d(n-1)
where "a1" is the first term and "d" is the common difference. The formula that matches a1=7 and d=12 is
B. a(n) = 7+(n-1)·12
<h2>
Answer:</h2>

or
4 to the 21st over 5 to the 6th.
<h2>
Step-by-step explanation:</h2>
First, we need to write our expression. Let's do it step by step:
<u>4 to the 7th:</u>

<u>5 squared:</u>

<u>4 to the 7th over 5 squared:</u>

<u>4 to the 7th over 5 squared all raised to the 3rd power:</u>
<u>
</u>
Using the law of exponents:

Finally, the answer is 4 to the 21st over 5 to the 6th.