Answer:
The sum of the first 880 terms in the sequence is 2,273,920.
Step-by-step explanation:
Arithmetic sequence:
The difference between consecutive terms is always the same, called common difference, and the nth term is given by:

In which d is the common difference.
Sum of the first n terms:
The sum of the first n terms of an arithmetic sequence is given by:

ai = ai-1 + 6
This means that 
In this question:
Sum of the first 800 terms, so 
First term is -53, so 
The 880th term is:

Sum

The sum of the first 880 terms in the sequence is 2,273,920.
Answer: The volume of the apartment is 2,160 ft3.
An hourly rating of 2.5 BTUs per cubic foot is required, so multiply the total volume by 2.5.
Arthur needs an air conditioner that will provide 5,400 BTUs to properly cool his apartment
Step-by-step explanation:
<h3>step 1.</h3>
use graph paper.
<h3>step 2.</h3>
draw lines thru the graph wait go on my image above!
<span>1.7a+0.3a=4/5
2a = 4/5
a = 4/5 * 1/2
a = 4/10
a = 2/5</span>
x = quarts of 30% acid solution
y = quarts of 65% solution
x + y = 175
Each quart of the 30% solution contributes 0.30x quarts of acid; similarly, each quart of the 65% solution contributes 0.65y quarts of acid. So
0.3x + 0.65y = 0.55*175 = 96.25
That is, the chemist wants 175 quarts of a new mixture with a 55% concentration of acid, which comes out to 95.25 total quarts of acid. The total amounts of acid from either sides of this equation must balance out.
Now solve for x and y:
x + y = 175 ==> y = 175 - x
0.3x + 0.65y = 96.25 ==> 0.3x + 0.65(175 - x) = 96.25
==> 0.3x + 113.75 - 0.65x = 96.25
==> 17.5 = 0.35x
==> x = 50 ==> y = 125