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Answer: 920</h3>
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Explanation:
The front face is a triangle with area of base*height/2 = 15*8/2 = 60 square feet.
The back face is identical to the front face, so we have another 60 square feet.
The left rectangular wall is 20 ft by 8 ft tall. Its area is 20*8 = 160 ft^2
The right slanted rectangular face is 20 ft by 17 ft. Its area is 20*17 = 340 ft^2
Lastly, the bottom rectangle floor is 15 ft by 20 ft to give an area of 15*20 = 300 ft^2
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To summarize so far
- Front face = 60 ft^2
- Back face = 60 ft^2
- Left face = 160 ft^2
- Right slanted face = 340 ft^2
- Bottom floor = 300 ft^2
Add up those areas to get the overall surface area.
60+60+160+340+300 = 920
The term "closed" in math means that if you take two items from a set, do some operation, then you'll always get another value in the same set (sometimes you may get the same value as used before). For example, adding two whole numbers leads to another whole number. We therefore say "the set of whole numbers is closed under addition". This applies to integers as well because integers are positive and negative whole numbers. So we can say that integers are closed under addition.
Integers are not closed under division. Take two integers like 2 an 5 and divide: 2/5 = 0.4 which is not an integer. Integers don't have decimal parts.
The set of whole numbers is {0,1,2,3,...} and we can subtract the two values 1 and 2 to get 1-2 = -1. The order matters here. Subtracting a larger value from a smaller leads to a negative. The value -1 is not in the set of whole numbers. So we can say that whole numbers is not closed under subtraction
Finally, the set of irrational numbers is closed under addition. Adding any two irrational numbers leads to another irrational number. For instance, pi+sqrt(2) = 3.142 + 1.414 = 4.556; I'm using rounded decimals as approximate values. An irrational number is one where we cannot write it as a fraction of integers. Contrast that with a rational number in which we can write it as a fraction of integers. Example: 10 = 10/1 is a rational number.
A) parallel, same slope
Y = 3x + b
9 = 3(5) + b
9 = 15 + b, b = -6
Equation: y = 3x - 6x
B) y = -7x + b
11 = -7 + b, b = 18
Y = -7x + 18
c) y = 9x + b
-16 = 18 + b, b = -34
d) y = -x + b
9 = 2 + b, b = 7
Y = -x + 7
Try the rest on your own
4 miles = 7,040 yards
Hope this helps!
