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3 years ago

What is 645 rounded to the nearest ten

Mathematics

2 answers:

givi [52]3 years ago

4 0

645 rounded to the nearest tenth is 640, because 5 rounds up.

Dmitry_Shevchenko [17]3 years ago

4 0

650 because 50 is closer than 30

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I need to find the surface area and volume of all three figures. If you could provide what equations you used to I will be grate

Margarita [4]

Answer:

Part 1) Sphere The surface area is equal to $SA=196\pi\ m^{2}$ and the volume is equal to $V=\frac{1,372}{3}\pi\ m^{3}$

Part 2) Cone The surface area is equal to $SA=(16+4\sqrt{65})\pi\ units^{2}$ and the volume is equal to $V=\frac{112}{3}\pi\ units^{3}$

Part 3) Triangular Prism The surface area is equal to $SA=51.57\ mm^{2}$ and the volume is equal to $V=17.388\ mm^{3}$

Step-by-step explanation:

Part 1) The figure is a sphere

a) Find the surface area

The surface area of the sphere is equal to

$SA=4\pi r^{2}$

we have

$r=14/2=7\ m$ ----> the radius is half the diameter

substitute

$SA=4\pi (7)^{2}$

$SA=196\pi\ m^{2}$

b) Find the volume

The volume of the sphere is equal to

$V=\frac{4}{3}\pi r^{3}$

we have

$r=14/2=7\ m$ ----> the radius is half the diameter

substitute

$V=\frac{4}{3}\pi (7)^{3}$

$V=\frac{1,372}{3}\pi\ m^{3}$

Part 2) The figure is a cone

a) Find the surface area

The surface area of a cone is equal to

$SA=\pi r^{2} +\pi rl$

we have

$r=4\ units$

$h=7\ units$

Applying Pythagoras Theorem find the value of l (slant height)

$l^{2}=r^{2} +h^{2}$

substitute the values

$l^{2}=4^{2} +7^{2}$

$l^{2}=65$

$l=\sqrt{65}\ units$

$SA=\pi (4)^{2} +\pi (4)(\sqrt{65})$

$SA=16\pi +4\sqrt{65}\pi$

$SA=(16+4\sqrt{65})\pi\ units^{2}$

b) Find the volume

The volume of a cone is equal to

$V=\frac{1}{3}\pi r^{2}h$

we have

$r=4\ units$

$h=7\ units$

substitute

$V=\frac{1}{3}\pi (4)^{2}(7)$

$V=\frac{112}{3}\pi\ units^{3}$

Part 3) The figure is a triangular prism

a) The surface area of the triangular prism is equal to

$SA=2B+PL$

where

B is the area of the triangular base

P is the perimeter of the triangular base

L is the length of the prism

Find the area of the base B

$B=\frac{1}{2} (2.7)(2.3)=3.105\ mm^{2}$

Find the perimeter of the base P

$P=2.7*3=8.1\ mm$

we have

$L=5.6\ mm$

substitute the values

$SA=2(3.105)+(8.1)(5.6)=51.57\ mm^{2}$

b) Find the volume

The volume of the triangular prism is equal to

$V=BL$

where

B is the area of the triangular base

L is the length of the prism

we have

$B=3.105\ mm^{2}$

$L=5.6\ mm$

substitute

$V=(3.105)(5.6)=17.388\ mm^{3}$

5 0

3 years ago

Hello there tiny humans can any you answer this pls for me

choli [55]

Answer:

1) B

2) a. 5x-7 b. 15b + 25 c. 16x^2 + 4x d. 13g -20. e. 6h + 23

Step-by-step explanation:

I’m sorry if any of them are wrong but I believe they’re right, most of it was distribution

3 0

4 years ago

Read 2 more answers

Matt brought $29.25 to the art supply store. He bought a brush, a sketchbook, and a paint set.

BartSMP [9]

The cost of the paint set is $14

<h3>What is the cost of the paint set?</h3>

Let:

p = cost of the paint set
cost of the sketch book = 3/4p
cost of the brush = 1/6(3/4p) = 1/8p

$29.25 = p + 3/4p + 1/8p + 3

$29.25 - $3 = p + 3/4p + 1/8p

$26.25 = 15/8p

p = (26.25 x 8) / 15

p = $14

Here is the complete question:

Matt brought $29.25 to the art supply store. He bought a brush, a sketchbook, and a paint set.

The brush was 1/6 as much as the sketchbook, and the sketchbook cost 3/4 the cost of the paint set.

Matt had $3.00 left over after buying these items. What is the cost of the paint set?

To learn more about fractions, please check: brainly.com/question/1114498

#SPJ1

4 0

2 years ago

What is −3 2/3⋅(−2 1/4) ? −8 1/4 −6 1/6 6 1/6 8 1/4

GalinKa [24]

-3 2/3 (-2 1/4)
= -11/3 * -9/4
= 99/12
= 8 3/12
= 8 1/4

In short, Your Answer would be Option D

Hope this helps!

3 0

3 years ago

Solve the following using substitution method

Wewaii [24]

Solution :

2a + 2b = 7 ...1)

4a + 3b = 12 ...2)

In equation, 1)

a = (7 - 2b)/2 ...3)

Putting value of a in equation 2) we get :

4 × (7 - 2b)/2 + 3b = 12

2( 7 - 2b ) + 3b = 12

14 - 4b + 3b = 12

b = 2

Putting value of b in 3) we get :

a = ( 7 - 2×2)/2

a = 3/2 = 1.5

Now,

2x - 3y = 16 ...5)

x + 2y = -6 ...6)

x = -6 - 2y

Putting above value of x in eq 5) , we get :

2( -6 - 2y ) - 3y = 16

-12 - 4y - 3y = 16

7y = -28

y = -4

x = -6 - ( 2× -4 )

x = 2

Hence, this is the required solution.

6 0

3 years ago