In mathematics, an empty set is a unique set having no elements inside it. Its size (which is based on the number of elements inside it) is also zero.
The empty set is sometimes called a null set as well.
Empty set is given the notation of o with a diagonal line through it as shown in the attached picture.
Answer:
The required expression is 
Step-by-step explanation:
Given : Percentage 
To find : Express the given percent as a decimal ?
Solution :
To convert percentage into decimal,
To remove percentage sign we divide the given number by 100.
So, 
Remove percentage,

Now, Put decimal after three digit

As we have to round it to five decimal places,

Therefore, The required expression is 
Answer:
Given: The following system:
4x + y − 2z=18 ......[1]
2x-3y+3z = 21 ......[2]
x-3y=6 ......[3]
we can write equation [3] as;
3y = x-6 ......[4]
Multiply by 3 in equation [1] to both sides of an equation we get,
or
12x+3y-6z=54 ......[5]
Substituting the equation [4] in [2] and [5] we get;
2x-(x-6)+3z=21 or
2x-x+6+3z=21
Simplify:
x+3z=15 .....[6] [combine like terms]
12x+x-6-6z =54
Simplify:
13x-6z=60 ......[7] [Combine like terms]
On Solving equation [6] and [7] simultaneously,
x+3z=15
13x-6z=60
we get the value of x
i.e, x=6
Substitute the value of x in equation x+3z=15 we get
6+3z=15 or
3z=9
Simplify:
z=3
Also, substitute the value of x=6 in equation [3] we get the value of y;
x-3y=6
6-3y=6 or
-3y = 0
Simplify:
y = 0
Therefore, the solution to the system of three linear equation is, (6, 0 , 3)
Hey You!
The images are blurry and I cannot make out most of the questions. I'll solve as many as I can see!
27. ANSWER:
Students A and D have a combined score of 0 because 4 + -4 = 0
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28. SOLUTION/ANSWER:
STEP 1: 12.40 - 0.72 = 11.68
STEP 2: 11.68/2 = 5.84
Answer: Each souvenir cost $5.84.
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29. SOLUTION/ANSWER:
(-68) - 214 = -282
Answer: The lowest elevation in California is -282 feet.
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33. SOLUTION/ANSWER:
60/3 = 20
Answer: The diver's change in depth was -20 per min.
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34. SOLUTION/ANSWER:
-43 - (-34) = -9. The difference between the two is -9.
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35. SOLUTION/ANSWER:
-64.4 + (3.22) = -67.62
Answer: Equals -67.62
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37. SOLUTION/ANSWER:
3.375 = 3 3/8 as a mixed number and 27/8 as an improper fraction.
Answer: 3 3/8 (or 27/8).
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38. SOLUTION/ANSWER:
3 ÷ 5 = 0.6
5 + 0.6 = 5.6
Answer: 5 3/5 = 5.6
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39. SOLUTION/ANSWER:
1.5 + 2.8 = 4.3
Haley jogged 4.3 km that day.
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I cannot see the other questions. If you can perhaps message them to me I can try to help you! :)