If you look at the numbers past the decimal point, the first digit - 8 - is in the tenths place. So, - 7 - is in the hundredths. What number is beside that? 4. When you round four, does it go up to ten or down to zero? Which is it closer to? The answer is zero.
So, the 7 in the hundredths place stays the same and any numbers after it are turned to zeros and cut off. Ending up with 26,379.87
        
             
        
        
        
2(3x+4y) = 2(24)
6x+8y = 48
Add both the equations 
 6x + 8y = 48
 + x - 8y = -20
—————————
 7x = 28
x = 28/7
x = 4
Plug in this value in the second equation
(4) - 8y = -20
-8y = -24
y = -24/-8
y = 3
Therefore:
x = 4
y = 3
        
             
        
        
        
Answ
Step-by-step explanation:
 
        
             
        
        
        
Answer:
(a)  P(x) = 300 x - 3600
(b)  P(340) = $ 98400
(c)  At least 12 items must be sold to avoid losing money.
Step-by-step explanation:
Part (a):
The Profit function is the difference between the revenue function (R(x)) and the Cost (C(x)) function: 
P(x) = R(x) - C(x)
P(x) = 384 x - [84 x + 3600]
P(x) = 384 x - 84 x - 3600
P(x) = 300 x - 3600
Part (b):
The profit on 340 items is: 
P(340) = 300 (340) - 3600
P(340) = 102000 - 3600
P(340) = $ 98400
Part (c):
To avoid losing money, the profit P(x) has to be larger or equal than zero. That is:
P(x)  0
 0
300 x -3600   0
 0
300 x   3600
 3600
x   3600/300
 3600/300
x   12
 12
So at least 12 items must be sold to avoid losing money.
 
        
             
        
        
        
For a variable to vary directly to another is telling you to set up a proportion
v/g = v/g
36/4 = v/11
4v = 396
v = 99