Answer:
14
Step-by-step explanation:
you have to add 3 to the first of the two numbers. for example 5+3=8 so the answer would be 58, and because you're decreasing each number by 10 you would have to add 1+3=4 so tha answer must be 14.
Here I am putting it in the picture.
Answer:
- total area is the total of the areas of each of the rectangular surfaces
- 67 units²
Step-by-step explanation:
Add up the surface areas of each of the 6 faces.
There are two top/bottom faces with the same area, two left/right faces with the same area, and two front/back faces with the same area. So you only need to figure the areas for 3 faces, then multiply that sum by 2. Of course the area of each rectangle is the product of its length and width. For length, width, and height dimensions L, W, and H, the total area is ...
A = 2(LW +WH +LH)
= 2(LW +H(L+W)) . . . . . I like this form because there's one less multiplication
= 2(5·4 + 1.5(5+4)) = 2(20 +13.5)
A = 67 . . . units²
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<em>Comment on dimensions</em>
It does not matter which number you use for length, width, or height. The problem is symmetrical that way, so any of the dimensions can be called any of those things. You need to use the same number consistently for height (for example) once you have made the choice of which is which.
Surface are of a rectangular prism = 2(l x w + l x h + w x h) = 2(10 x 3 + 10x + 3x) = 2(30 + 13x) = 60 + 26x
Volume of a rectangular prism = l x w x h = 10 * 3 * x = 30x
Since surface area = volume
60 + 26x = 30x
4x = 60
x = 15 in
