Solve for X: A=2B/x+3

Work out the surface area of a cylinder when the height = 18cm and the volume = 1715cm cubed

lara [203]

Answer:

813.4 cm² (nearest tenth)

Step-by-step explanation:

Volume of a cylinder

$\sf V=\pi r^2 h \quad\textsf{(where r is the radius and h is the height)}$

Given:

h = 18cm
V = 1715 cm³

Use the Volume of a Cylinder formula and the given values to find the radius of the cylinder:

$\implies \sf 1715=\pi r^2 (18)$

$\implies \sf r^2=\dfrac{1715}{18 \pi}$

$\implies \sf r=\sqrt{\dfrac{1715}{18 \pi}$

Surface Area of a Cylinder

$\sf SA=2 \pi r^2 + 2 \pi r h \quad\textsf{(where r is the radius and h is the height)}$

Substitute the given value of h and the found value of r into the formula and solve for SA:

$\implies \sf SA=2 \pi \left(\sqrt{\dfrac{1715}{18 \pi}\right)^2 + 2 \pi \left(\sqrt{\dfrac{1715}{18 \pi}\right)(18)$

$\implies \sf SA=2 \pi \left(\dfrac{1715}{18 \pi} \right) + 36 \pi \left(\sqrt{\dfrac{1715}{18 \pi}\right)$

$\implies \sf SA=\dfrac{1715}{9} + 36 \pi \left(\sqrt{\dfrac{1715}{18 \pi}\right)$

$\implies \sf SA=813.3908956...$

Therefore, the surface area of the cylinder is 813.4 cm² (nearest tenth)

8 0

2 years ago

Read 2 more answers

If there are initially 2000 bacterial in a culture, and the number of bacteria doubles each hour, the number of bacteria after t

Nezavi [6.7K]

Replace 7 for the variable, t. N= 2000(2(7))= 28000

7 0

3 years ago

Read 2 more answers

Henrietta buys twelve pounds of bananas and ten pounds of apples for $ 12 . Gustavo buys eight pounds of bananas and five pounds

Olegator [25]

Answer:

The price per pound of bananas is $0.5 and the price per pound of apples is $0.6

Step-by-step explanation:

Let

x -----> the price per pound of bananas

y -----> the price per pound of apples

we know that

12x+10y=12 -----> equation A

8x+5y=7 ----> equation B

Solve the system of equations by graphing

Remember that the solution is the intersection point both graphs

The intersection point is (0.5,0.6)

see the attached figure

therefore

The price per pound of bananas is $0.5

The price per pound of apples is $0.6

4 0

3 years ago

Y varies directly with x. If x = -12 when y = -3, which equation represents this situation?

Vitek1552 [10]

Answer:

y = 3x over 4

Step-by-step explanation:

3 0

3 years ago

A college some completed some courses worth 3 credits and some courses worth 4 credits. The students earned a total of 59 credit

Law Incorporation [45]

The student completed 13 courses with 3 credit hours.

Step-by-step explanation:

Total credit hours = 59 credits hours

Total courses = 18

Let,

3 credit hours courses = x

4 credit hours courses = y

According to statement;

x+y=18 Eqn 1

3x+4y=59 Eqn 2

Multiplying Eqn 1 by 3

$3(x+y=18)\\3x+3y=54\ \ \ Eqn\ 3$

Subtracting Eqn 3 from Eqn 2

$(3x+4y)-(3x+3y)=59-54\\3x+4y-3x-3y=5\\y=5$

Putting y=5 in Eqn 1

$x+5=18\\x=18-5\\x=13$

The student completed 13 courses with 3 credit hours.

Keywords: linear equation, elimination method

Learn more about linear equations at:

#LearnwithBrainly

3 0

3 years ago