Answer:
X=6
Step-by-step explanation:
Answer:
The answer is 4.
Step-by-step explanation:
2(1 - 3y) - 13x
2(1−(3)(−9))−(13)(4)
56-52
=4
Answer:
12a. 471.2 cm²
12b. 60 m²
Step-by-step explanation:
Part A.
The surface area of each figure is the sum of the end area and the lateral area.
<u>cylinder</u>
S = (2)(πr²) +2πrh = 2πr(r +h)
S = 2π(5 cm)(5 cm +10 cm) =150π cm² ≈ 471.2 cm²
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<u>triangular prism</u>
S = (2)(1/2)bh + PL . . . . b=triangle base; h=triangle height; P=triangle perimeter; L=length of prism
S = (4 m)(1.5 m) + ((4 + 2·2.5) m)(6 m) = (6 + 54) m² = 60 m²
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Part B.
Surface area is useful in the real world wherever products are made from sheets of material or wherever coverings are applied.
Carpeting or other flooring, paint, wallpaper are all priced in terms of the area they cover, for example.
The amount of material used to make containers in the shapes shown will depend on the area of these containers (and any material required for seams).
We can factor this by using grouping. Take the leading coefficient and multiply it by the constant. In this case we get 5*-7 = -35.
Now we need 2 numbers that add to 2 and multiply to be -35. The numbers are -5 and 7.
So split the 2r into these two terms and group.
(5r^2 - 5r) + (7r - 7)
Factor both groups.
5r(r-1) + 7(r-1)
The factors of (r-1) can be added together to get the answer.
(r-1)(5r+7)
