7x-6=5(x+4)
7x-6=5x+20
-5x -5x
2x-6=20
+6 +6
2x=26
/2 /2
X=13
The <em>total</em> area of all six faces of the tunnel is 
square centimeters.
<h2>Procedure - Surface area of a tunnel for a toy train</h2>
The surface area of the solid (
) used to represent the tunnel for a toy train is the sum of its six faces (two <em>semicircular</em> sections, inner <em>semicircular</em> arc section, outer <em>semicircular</em> arc section, two rectangles).
<h3>Determination of the surface area of the tunnel based on information of the diagram</h3>
We calculate the surface area as following:
![A = 2\cdot \frac{\pi}{2} \cdot [(10\,cm)^{2}-(8\,cm)^{2}] + \pi\cdot (8\,cm)\cdot (30\,cm) + \pi\cdot (10\,cm)\cdot (30\,cm) + 2\cdot (2\,cm)\cdot (30\,cm)](https://tex.z-dn.net/?f=A%20%3D%202%5Ccdot%20%5Cfrac%7B%5Cpi%7D%7B2%7D%20%5Ccdot%20%5B%2810%5C%2Ccm%29%5E%7B2%7D-%288%5C%2Ccm%29%5E%7B2%7D%5D%20%2B%20%5Cpi%5Ccdot%20%288%5C%2Ccm%29%5Ccdot%20%2830%5C%2Ccm%29%20%2B%20%5Cpi%5Ccdot%20%2810%5C%2Ccm%29%5Ccdot%20%2830%5C%2Ccm%29%20%2B%202%5Ccdot%20%282%5C%2Ccm%29%5Ccdot%20%2830%5C%2Ccm%29)
The <em>total</em> area of all six faces of the tunnel is square centimeters. 
To learn more on surface areas, we kindly invite to check this verified question: brainly.com/question/2835293
Answer:
$16
Step-by-step explanation:
Looking at the Price for 5 Items (10 dollars), That means the Price Per Item Is 2 dollars. Now we know the Cost per Item, We need to multiply the Cost per item by 8 (2*8) making it 16.
Answer:
I think it is five but I cannot see all the lines too well so I don't know
He has six pieces ribbon and one little piece that is 0.2 meters long
