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3 years ago

What is the area of a semicircle with a diameter of 21.5

Mathematics

1 answer:

denis-greek [22]3 years ago

7 0

Area of a circle = PI x R^2

r = 1/2 diameter

r = 21.5/2

r = 10.75

Area of circle = 3.14 x 10.75^2 = 3.14 x 115.5625 = 362.86625 square units.

A semicircle is half a circle:

Area of semicircle = 362.86625 / 2 = 181.433125 square units (round the answer as needed).

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Can someone solve this? Im lost .......

Westkost [7]

A.; 14 doesn’t work and neither does 8 or 3.

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2 years ago

HELP ASAP ...........

dedylja [7]

Answer:

Step-by-step explanation:

Given

y - 2x - 8 = 0 ( add 2x + 8 to both sides )

y = 2x + 8 → (1)

y² + 8x = 0 → (2)

Substitute y = 2x + 8 into (2)

(2x + 8)² + 8x = 0 ← expand left side using FOIL and simplify

4x² + 32x + 64 + 8x = 0

4x² + 40x + 64 = 0 ( divide through by 4 )

x² + 10x + 16 = 0 ← in standard form

(x + 8)(x + 2) = 0 ← in factored form

x + 8 = 0 ⇒ x = - 8

x + 2 = 0 ⇒ x = - 2

Substitute these values into (1) for corresponding values of y

x = - 8 : y = 2(- 8) + 8 = - 16 + 8 = - 8 ⇒ P (- 8, - 8)

x = - 2 : y = 2(- 2) + 8 = - 4 + 8 = 4 ⇒ Q (- 2, 4 )

Calculate the length of PQ using the distance formula

PQ = $\sqrt{(x_{2}-x_{1})^2+(y_{2}-y_{1})^2 }$

with (x₁, y₁ ) = P (- 8, - 8) and (x₂, y₂ ) = Q (- 2, 4 )

PQ = $\sqrt{(-2-(-8))^2+(4-(-8))^2}$

= $\sqrt{(-2+8)^2+(4+8)^2}$

= $\sqrt{6^2+12^2}$

= $\sqrt{36+144}$

= $\sqrt{180}$

= $\sqrt{36(5)}$

= $\sqrt{36}$ × $\sqrt{5}$

= 6 $\sqrt{5}$ → A

8 0

2 years ago

What is the decimal multiplier to decrease by 72%?

mixer [17]

Answer:

0.28

Step-by-step explanation:

Given in question that,we have to decrease by 72%.that means from 100% of total, 72% should be decreased. that means an overall of 28% will be left. so if you make a number into 28% of it, it implies that you have decreased that number by 72%.so from this,we can say that we have to make the number 28%.that means we have to multiply the number with 28/100 which is equal to 0.28.

4 0

3 years ago

Read 2 more answers

Alejandra currently has a balance of $2,254 in her checking account. She deposits a $873.84 paycheck, a $25 rebate check, and a

zaharov [31]

Answer:

$3160.84

Step-by-step explanation:

2254 + 873.84 + 25 + 358 = 3510.84

3510.84 - 350 = 3160.84

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2 years ago

What is the inverse of the function f(x) = 2x + 1?

mamaluj [8]

Answer: y=(x-1)/2

Step-by-step explanation:

To find the inverse, you want to switch the y with x and x with y. Then, you solve.

y=2x+1 [switch y with x and x with y]

x=2y+1 [subtract both sides by 1]

x-1=2y [divide both sides by 2]

(x-1)/2=y

Now, we know that y=(x-1)/2 is the inverse.

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2 years ago