Answer:
x = 2
Step-by-step explanation:
2(2x+1-x)=6
2(x+1)=6 add common factors
2x+2=6 distribute the 2
2x=4 subrtract 2 on both sides
x=2 divide 2 on both sides
Its 81 centimeters because you round 5 and over. So nearest centimeter means 2 whole numbers which is 81
Answer:
C. (see the attachment)
Step-by-step explanation:
Both inequalities include the "or equal to" case, so both boundary lines will be solid. That excludes choices A and D.
The first inequality is plotted the same way in all graphs, so we must look at the second inequality. The relationship of y and the comparison symbol is ...
-y ≥ (something)
If we multiply by -1, we get ...
y ≤ (something else)
This means the solution space will be <em>on or below (less than or equal to) the boundary line</em>. This is the shaded area in graph C. (Graph B shows shading <em>above</em> the line.)
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<em>Further comment</em>
Since the boundary for the second inequality is fairly steep, "above" and "below" the line can be difficult to see. Rather, you can consider the relationship of x to the comparison symbol. For the second inequality, that is ...
x ≥ (something)
indicating the solution space is <em>on or to the right of the boundary line</em>.
Answer:
The room dimensions for a minimum cost are: sides of 10 feet and height of 8.75 feet.
Step-by-step explanation:
We have a rectangular room with sides x and height y.
The volume of the room is 875 cubic feet, and can be expressed as:

With this equation we can define y in function of x as:

The cost of wall paint is $0.08 per square foot. We have 4 walls which have an area Aw:

The cost of ceiling paint is $0.14 per square foot. We have only one ceiling with an area:

We can express the total cost of painting as:

To calculate the minimum cost, we derive this function C and equal to zero:
![\dfrac{dC}{dx}=280(-1)\dfrac{1}{x^2}+0.14(2x)=0\\\\\\-\dfrac{280}{x^2}+0.28x=0\\\\\\0.28x=\dfrac{280}{x^2}\\\\\\x^3=\dfrac{280}{0.28}=1000\\\\\\x=\sqrt[3]{1000} =10](https://tex.z-dn.net/?f=%5Cdfrac%7BdC%7D%7Bdx%7D%3D280%28-1%29%5Cdfrac%7B1%7D%7Bx%5E2%7D%2B0.14%282x%29%3D0%5C%5C%5C%5C%5C%5C-%5Cdfrac%7B280%7D%7Bx%5E2%7D%2B0.28x%3D0%5C%5C%5C%5C%5C%5C0.28x%3D%5Cdfrac%7B280%7D%7Bx%5E2%7D%5C%5C%5C%5C%5C%5Cx%5E3%3D%5Cdfrac%7B280%7D%7B0.28%7D%3D1000%5C%5C%5C%5C%5C%5Cx%3D%5Csqrt%5B3%5D%7B1000%7D%20%3D10)
The sides of the room have to be x=10 feet.
The height can be calculated as:

The room will have sides of 10 feet and a height of 8.75 feet.