Answer:
9x -2
Step-by-step explanation:
(7x + 3) + (4x - 1) - (2x + 4)
Distribute the minus sign
(7x + 3) + (4x - 1) - 2x - 4
Combine like terms
7x+4x-2x +3 -1-4
9x -2
Answer: Choice C) 124 square cm
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Explanation:
Let's calculate the area of the trapezoid shown
b1 and b2 are the parallel bases; h is the height of the 2D trapezoid
b1 = 2
b2 = 5
h = 1.5
A = h*(b1+b2)/2
A = 1.5*(2+5)/2
A = 1.5*7/2
A = 10.5/2
A = 5.25
The area of one 2D trapezoid is 5.25 sq cm
There are two of these trapezoids that form the base faces of the trapezoidal prism. So the total base area is 2*5.25 = 10.5 sq cm
Keep this value (10.5) in mind. We'll use it later.
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Now onto the lateral surface area (LSA)
It turns out that the formula for the LSA is
LSA = p*d
where
p = perimeter of the trapezoid shown
d = depth or height of the 3D trapezoid (I'm not using h as it was used earlier)
This formula works for any polygonal base. It doesn't have to be a trapezoid.
In this case the perimeter is,
p = 1.7+2+2.65+5
p = 11.35
So
LSA = p*d
LSA = 11.35*10
LSA = 113.5
Add this LSA to the base area found earlier
10.5+113.5 = 124
The total surface area is 124 square cm
The caret (^) is the symbol conventionally used to indicate an exponent.
You have
area = 2.76·10^12
width = 4.6·10^5
You want to find the perimeter of the rectangle with these dimensions.
The perimeter of a rectangle is twice the sum of length and width.
perimeter = 2*(length + width)
The length can be figured from the area using the formula for area.
area = length*width
area/width = length . . . . . . . . . divide by width
Filling in the numbers, we have
perimeter = 2*((2.76·10^12)/(4.6·10^5) +(4.6·10^5))
perimeter = 2*(6.0·10^6 +0.46·10^6)
perimeter = 2*6.46·10^6 = 1.292·10^7
The perimeter of the rectangle is ...
1.292·10^7
