If you use a laptop: 9.25; a desktop with a CRT monitor: 55.51; a desktop with an LCD monitor: 46.26.
A laptop that is plugged up and turned off uses 0.001kw/hr of energy. Each kwh of energy produces, on average, 1.39 lbs of CO2. There are 24*7=168 hours in the week; subtract the 40 hour work week from this and we have 128 hours a week for 52 weeks a year:
0.001*128*52=6.656*1.39=9.25.
A desktop that is plugged up and turned off uses 0.004kw/hr of energy. A CRT monitor uses 0.002 kw/hr when turned off. This means we have:
(0.004*128*52*1.39)+(0.002*128*52*1.39)=55.51.
For a desktop and an LCD monitor, which uses 0.001 kw/hr of energy, we have:
(0.004*128*52*139)+(0.001*128*52*1.39)=46.26.
The total amount is "x", so, if 22.8 is 58%, "x" is the 100%,
Answer:
The answer to your question is: first piece = 4 in, second piece = 8 in, third piece = 12 in
Step-by-step explanation:
Data
total length = 24 inches
first piece = x in
second piece = 2x
third piece = 3x
Equation
x + 2x + 3x = 24
6x = 24
x = 24/6
x = 4 length of the first piece
second piece = 2(4) = 8 inches
third piece = 3(4) = 12 inches
-x + 5y = 8
multiply this equation by 3
-3x + 15y = 24
now add it to the other equation ( elimination)
-3x + 15y = 24
3x + 7y = -2
-----------------------
0x + 22 y = 22
divide each side by 22
y =1
substitute into -x + 5y =8 to find x
-x + 5(1) = 8
-x + 5 = 8
-x =3
divide by -1
x =-3
Answer (-3,1)
Choice A
