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3 years ago

The circumference of a circle is 5 Pi cm. What is the area of the circle?

Mathematics

2 answers:

telo118 [61]3 years ago

6 0

Answer:

6.25 $\pi$ or and estimated answer of 19.625

Step-by-step explanation:

C = 2R $\pi$

Since 2R = D, the diameter is 5 cm and the radius is 2.5 cm

(D = diameter) (R = radius)

The area of a circle is $R^{2}$ $\pi$

So 2.5 squared equals 6.25

The area of this circle is 6.25 $\pi$

or and estimated answer of 19.625

(6.25 times pi)

Ber [7]3 years ago

4 0

Answer:

6.25 pi cm^2

Step-by-step explanation:

The formula for circumference is

C = 2*pi*r

We know the circumference is 5 pi

5 pi = 2 * pi *r

Divide each side by pi

5 pi/pi = 2 * pi *r/pi

5 = 2r

Divide by 2

5/2 = 2r/2

2.5 = r

We need to find the area of the circle

The area is given by

A = pi * r^2

= pi * (2/5)^2

= pi *6.25

= 6.25 pi cm^2

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Answer:

4x2 + 23x – 72

= (4x - 9)(x+8)

Step-by-step explanation:

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2 years ago

A cash box contains $74 made up of quarters, half-dollars, and one-dollar

Strike441 [17]

Answer:

25 one-dollar coins, 16 half-dollar coins, and 164 quarters

Step-by-step explanation:

First, set up equations based on the information given:

$0.25q+0.50h+1.00d=74$

$\displaystyle{h=\frac{3}{5}d+1}$

$q=4(d+h)$

Then, substitute q in the first equation with the expression from the third equation:

$0.25[4(d+h)]+0.50h+1.00d=74\\1d+1h+0.50h+1.00d=74\\2d+1.5h=74$

Next, substitute h in that equation with the expression from the second equation:

$\displaystyle{2d+1.5(\frac{3}{5}d+1)=74}$

$2d+0.9d+1.5=74\\2.9d+1.5=74$

Solve for d, the number of one-dollar coins:

$2.9d+1.5=74\\2.9d=72.5\\d=25$

Substitute 25 for d in the second equation to find h, the number of half-dollar coins:

$\displaystyle{h=\frac{3}{5}d+1}$

$\displaystyle{h=\frac{3}{5}(25)+1}$

$h=15+1\\h=16$

Substitute 25 for d and 16 for h in the third equation to find q, the number of quarters:

$q=4(d+h)\\q=4(25+16)\\q=4(41)\\q=164$

Then, verify that the coins total $74:

$0.25(164)+0.50(16)+1.00(25)=74\\41+8+25=74\\74=74\\\text{Check.}$

Next, verify that the number of half-dollar coins is one more than three-fifths of the number of one-dollar coins:

$\displaystyle{h=\frac{3}{5}d+1}$

$\displaystyle{16=\frac{3}{5}(25)+1}$

$16 = 15 + 1\\16 = 16\\\text{Check.}$

Finally, verify that the number of quarters is four times the number one-dollar and half-dollar coins together:

$q=4(d+h)\\164=4(25+16)\\164=4(41)\\164=164\\\text{Check.}$

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3 years ago

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2 years ago

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2 years ago

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The ratio of boys to girls in Mrs. Miller's class is 2:3. If there are 8 boys in her class, how many girls are there?

Alenkasestr [34]

Answer:12

for every 2 boys that is 3 girls

there are 4 sets of two boys so you would have 4 sets of 3 girls

4×3=12

I hope this is good enough:

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2 years ago