Answer:

Step-by-step explanation:

Apply sum of cubes formula: 


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
__
<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
_____
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).
Answer:
Results are below.
Step-by-step explanation:
<u>First, we need to calculate the variable income per job:</u>
<u />
First job= 450 - 150= 300
Second job= 675 - 150= 525
<u>Now, the hourly rate:</u>
<u></u>
Hourly rate= total variable income / number of hours
First job= 300 / 4= $75
Second job= 525 / 3= $175
It is probably that the second job was 7 hours long. If not, he doesn't charge the same amount per hour
The price per cubic inch for the extra large tub will probably be 2000