A). The second one and the fourth one combined make the object ( a )
B). First one and the last one combined make the object ( b )
C). First one and the third one combined make the object ( c )
<span>I will assume the more likely selection of $10 per sandal as opposed to $0.05 per sandal.
So with the formulas
c = 1000 + 5x
r = 75x - 0.4x^2
Sandals Cost Revenue Profit or Loss
0 $1,000.00 $0.00 -$1,000.00
1 $1,005.00 $74.60 -$930.40
2 $1,010.00 $148.40 -$861.60
3 $1,015.00 $221.40 -$793.60
4 $1,020.00 $293.60 -$726.40
5 $1,025.00 $365.00 -$660.00
6 $1,030.00 $435.60 -$594.40
7 $1,035.00 $505.40 -$529.60
8 $1,040.00 $574.40 -$465.60
9 $1,045.00 $642.60 -$402.40
10 $1,050.00 $710.00 -$340.00
11 $1,055.00 $776.60 -$278.40
12 $1,060.00 $842.40 -$217.60
13 $1,065.00 $907.40 -$157.60
14 $1,070.00 $971.60 -$98.40
15 $1,075.00 $1,035.00 -$40.00
16 $1,080.00 $1,097.60 $17.60
17 $1,085.00 $1,159.40 $74.40
18 $1,090.00 $1,220.40 $130.40
19 $1,095.00 $1,280.60 $185.60
20 $1,100.00 $1,340.00 $240.00
As you can see 16 sandals and up is profitable.
At what production levels will the company lose money?
a. between 0 and 10 or between 150 and 190 pairs, inclusive
150 and 190
c. between 10 and 20 or between 50 and 100, inclusive
If you add up the profit between 10 and 20 you will get $-484 so 50 and 100
b. between 0 and 15 or between 160 and 200 pairs, inclusive
160 and 200
d. between 15 and 35 or between 75 and 125, inclusive
Neither 15 and 35 or 75 and 125 will lose money.</span>
The answer correct answer is 80.5
Remark
I'm going to interpret this equation as
D = ut + kt² The only difference is the 2.
Solution
Subtract kt² from both sides.
D - kt² = ut Now divide by u on both sides.

The t's cancel out. on the right. You are left with u on the right.
