Answer:
i beleive it is c
Step-by-step explanation:
Answer:
=> -2.22
Step-by-step explanation:
=> 2.35 + ( -4.57)
=> 2.35 - 4.57
=> - 2.22
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:
![V=x^2y=875](https://tex.z-dn.net/?f=V%3Dx%5E2y%3D875)
With this equation we can define y in function of x as:
![x^2y=875\\\\y=\dfrac{875}{x^2}](https://tex.z-dn.net/?f=x%5E2y%3D875%5C%5C%5C%5Cy%3D%5Cdfrac%7B875%7D%7Bx%5E2%7D)
The cost of wall paint is $0.08 per square foot. We have 4 walls which have an area Aw:
![A_w=xy=x\cdot \dfrac{875}{x^2}=\dfrac{875}{x}](https://tex.z-dn.net/?f=A_w%3Dxy%3Dx%5Ccdot%20%5Cdfrac%7B875%7D%7Bx%5E2%7D%3D%5Cdfrac%7B875%7D%7Bx%7D)
The cost of ceiling paint is $0.14 per square foot. We have only one ceiling with an area:
![A_c=x^2](https://tex.z-dn.net/?f=A_c%3Dx%5E2)
We can express the total cost of painting as:
![C=0.08\cdot (4\cdot A_w)+0.14\cdot A_c\\\\C=0.08\cdot (4\cdot \dfrac{875}{x})+0.14\cdot x^2\\\\\\C=\dfrac{280}{x}+0.14x^2](https://tex.z-dn.net/?f=C%3D0.08%5Ccdot%20%284%5Ccdot%20A_w%29%2B0.14%5Ccdot%20A_c%5C%5C%5C%5CC%3D0.08%5Ccdot%20%284%5Ccdot%20%5Cdfrac%7B875%7D%7Bx%7D%29%2B0.14%5Ccdot%20x%5E2%5C%5C%5C%5C%5C%5CC%3D%5Cdfrac%7B280%7D%7Bx%7D%2B0.14x%5E2)
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:
![y=875/x^2=875/(10^2)=875/100=8.75](https://tex.z-dn.net/?f=y%3D875%2Fx%5E2%3D875%2F%2810%5E2%29%3D875%2F100%3D8.75)
The room will have sides of 10 feet and a height of 8.75 feet.
Answer:
pointing towards the top
Step-by-step explanation:
1.5 feet long 2.5 feet wide the suitcase is so straight
HOPE OT HELPS