The average value is given by

Setting

, you get

, and the integral becomes


Answer:
D
Step-by-step explanation:

Which is about .57
I think it's D. (sorry if i'm wrong)
You need to find the amount subject to withholding, subtracting from the weekly salary the amount for one withholding allowance for weekly salaries, which is 77.90$:
830 - 77.90 = 752.1 $.
Then, look in the Fed Tax tables (
http://www.opers.ok.gov/Websites/opers/images/pdfs/2016-Fed-Tax-Tables.pdf ) for a married person with a weekly payroll.
You previously found an amount of 752.1 which is greater than 521 but less than 1613$: therefore the income tax to withhold is 35.70$ + 15% of excess over $521.
Therefore, calculate the income tax due: 35.70 + (752.1 - 521) × 15 ÷ 100 = 70.37$
The total amount of income tax that will be withheld is 70.37$
<span>
<span>1st</span></span><span> formula 2n + 3m = 280
</span><span><span>
</span><span>2nd</span></span><span> formula 2n + 5m = 320
</span><span><span>
</span><span>rearrange 1st</span> formula to equal n:</span>
<span><span>2n = -3m + 280
</span>
</span><span>n = -3/2
m + 140
</span><span><span>
</span><span>rearrange 2nd</span> formula to equal n:</span>
<span><span>2n = -5m + 320
</span>
</span><span>n = -5/2m + 160
</span><span><span>
so now you have
</span>-3/2m + 140 = -5/2m + 160 </span>
<span><span>Rearrange to become:
</span>
</span><span><span>-3/2m + 5/2m = 160 - 140
</span>
</span><span>m = 20
</span><span>
</span>
<span>Now place 20 into the very 1st</span><span><span> equation in place
of the letter m
</span>
</span><span><span>2n + 3(20) = 280
</span>
</span><span><span>2n + 60 = 280
</span>
</span><span><span>2n = 220
</span>
</span><span>n = 110
</span><span><span>
</span>so it costs $110 per night, $20 per meal</span>