Hello there.
<span>Which numbers are necessary to solve this problem?
Brian goes to the gym 3 times a week. He exercises for 45 minutes each visit. Fifteen of those minutes are spent on weights and the rest are spent on the treadmill.
How much time does Brian spend on the treadmill in 4 weeks?
Answer: </span><span>3 times a week, 45 minutes, 15 minutes, 4 weeks
</span>
21.07 beacuse when you add them all up you get that..
Answer:
The 13th term is 81<em>x</em> + 59.
Step-by-step explanation:
We are given the arithmetic sequence:

And we want to find the 13th term.
Recall that for an arithmetic sequence, each subsequent term only differ by a common difference <em>d</em>. In other words:

Find the common difference by subtracting the first term from the second:

Distribute:

Combine like terms. Hence:

The common difference is (7<em>x</em> + 5).
To find the 13th term, we can write a direct formula. The direct formula for an arithmetic sequence has the form:

Where <em>a</em> is the initial term and <em>d</em> is the common difference.
The initial term is (-3<em>x</em> - 1) and the common difference is (7<em>x</em> + 5). Hence:

To find the 13th term, let <em>n</em> = 13. Hence:

Simplify:

The 13th term is 81<em>x</em> + 59.