I can’t figure it out!! Please help!

in the number 8.88, how is the value of the underlined digit related to the digits on its left and right?

nikklg [1K]

Digits on the right are like units and digits on the left are like tenths

7 0

2 years ago

You have a wire that is 20 cm long. You wish to cut it into two pieces. One piece will be bent into the shape of a square. The o

Aleksandr [31]

Answer:

Therefore the circumference of the circle is $=\frac{20\pi}{4+\pi}$

Step-by-step explanation:

Let the side of the square be s

and the radius of the circle be r

The perimeter of the square is = 4s

The circumference of the circle is =2πr

Given that the length of the wire is 20 cm.

According to the problem,

4s + 2πr =20

⇒2s+πr =10

$\Rightarrow s=\frac{10-\pi r}{2}$

The area of the circle is = πr²

The area of the square is = s²

A represent the total area of the square and circle.

A=πr²+s²

Putting the value of s

$A=\pi r^2+ (\frac{10-\pi r}{2})^2$

$\Rightarrow A= \pi r^2+(\frac{10}{2})^2-2.\frac{10}{2}.\frac{\pi r}{2}+ (\frac{\pi r}{2})^2$

$\Rightarrow A=\pi r^2 +25-5 \pi r +\frac{\pi^2r^2}{4}$

$\Rightarrow A=\pi r^2\frac{4+\pi}{4} -5\pi r +25$

For maximum or minimum $\frac{dA}{dr}=0$

Differentiating with respect to r

$\frac{dA}{dr}= \frac{2\pi r(4+\pi)}{4} -5\pi$

Again differentiating with respect to r

$\frac{d^2A}{dr^2}=\frac{2\pi (4+\pi)}{4}$ > 0

For maximum or minimum

$\frac{dA}{dr}=0$

$\Rightarrow \frac{2\pi r(4+\pi)}{4} -5\pi=0$

$\Rightarrow r = \frac{10\pi }{\pi(4+\pi)}$

$\Rightarrow r=\frac{10}{4+\pi}$

$\frac{d^2A}{dr^2}|_{ r=\frac{10}{4+\pi}}=\frac{2\pi (4+\pi)}{4}>0$

Therefore at $r=\frac{10}{4+\pi}$ , A is minimum.

Therefore the circumference of the circle is

$=2 \pi \frac{10}{4+\pi}$

$=\frac{20\pi}{4+\pi}$

4 0

2 years ago

Solve this inequality 3q - 6 > 21

erica [24]

3q - 6 > 21

3q > 27

q > 9

6 0

2 years ago

Read 2 more answers

It costs Guido $0.20 per minute to forward voicemail messages as texts to his cell phone. He already spent $4 in forwarding mess

Vaselesa [24]

Answer:

10 minutes

Step-by-step explanation:

Let the number of minutes = x

It costs Guido $0.20 per minute to forward voicemail messages as texts to his cell phone. He already spent $4 in forwarding messages this month.

For Guido

$4 + 0.20x

His mom has spent $2 forwarding messages. It costs her $0.40 per minute so she can call long distance.

For his mum

$2 + 0.40x

Guido's mom said they have to spend the same amount.

Equating both Equations together

$4 + 0.20x = $2 + 0.40x

$4 - $2 = 0.40x - 0.20x

2 = 0.20x

x = 2/0.20

x = 10 minutes

Guido can talk for 10 minutes

8 0

2 years ago

The combined height of one fir tree and one pine tree is 212121 meters. The height of 444 fir trees stacked on top of each other

Drupady [299]

Answer:

Height of fir tree = 9 meters

height of pine tree= 12 meters

Step-by-step explanation:

The combined height of one fir tree and one pine tree is 21 meters. The height of 4 fir trees stacked on top of each other is 24 meters taller than one pine tree.

Let x be the height of fir tree and y be the height of pine tree

$x+y=21$

Subtract x from both sides

$y=21-x$

height of 4 fir trees = pine tree +24

$4x=y+24$

Substitute 21-x or y in the above equation

$4x=21-x+24$

Add x on both sides

$5x=45$

Divide by 5 on both sides

x=9

Now plug in 9 for x and find out y

$y=21-x$

$y=21-9$

y=12

Height of fir tree = 9 meters

height of pine tree= 12 meters

4 0

3 years ago