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3 years ago

Help please! im really confused and stuck

Mathematics

1 answer:

vesna_86 [32]3 years ago

7 0

To find the area of a circle, use the following formula; A = πr^2

The radius of a circle is half the diameter.

So;

4.) 18/2 = 9

Radius = 9

(3.14)9^2

9(9) = 81(3.14)

254.34 is the area of figure #4.

5.) 12/2 = 6

A = (3.14)(6)^2

A = (3.14)(36)

113.04(2) Because there are two pizzas.

226.08

Number 4 gives the most amount of pizza. So, one 18 in. pizza.

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Help me with this!! NO FAKE ANSWERS!!

Ksju [112]

Answer:

Step-by-step explanation:

this is a similar triangle, so the side that is 6 and 18 will have the same ratio as the side 4 and x, then

6/18 = 4 / x

x = 4 * 18/6

x = 2 * 18 / 3

x = 36 /3

x = 12

nice :)

7 0

3 years ago

In a public show 75 % of seats were filled if there were 600 seats in the hall, how many seats were vacant ?

harina [27]

600x0.25 = 150 seats left vacant.

7 0

3 years ago

Read 2 more answers

Need help plzzzz will medal and fan

andriy [413]

The answer is f(x)=x²+2x when evaluated with -3 gives you the value of 3

Let's check all functions.
1. The function f(x)=x²+2x when evaluated with 3 gives you the value of 3:
Evaluated with x means that x = 3.
f(3) = 3² + 2 * 3 = 9 + 6 = 15
15 ≠ 3, so, this is not correct.

2. f(x)=x²-3x when evaulated with -3 give you the value of 3
Evaluated with -3 means that x = -3.
(f-3) = (-3)² - 3 * (-3) = 9 + 9 = 18
18 ≠ 3, so, this is not correct.

3. f(x)=x²+2x when evaluated with -3 gives you the value of 3
 Evaluated with -3 means that x = -3.
f(-3) = (-3)² + 2 * (-3) = 9 - 6 = 3
3 = 3, so this is correct.

4. f(x)=x²-3x when evaluated with -3 gives you the value of 3
Evaluated with 3 means that x = 3.
f(3) = (3)² - 3 * 3 = 9 - 9 = 0
0 ≠ 3, so this is not correct.

6 0

4 years ago

Read 2 more answers

Rationalize the denominator of sqrt -49 over (7 - 2i) - (4 + 9i)

zubka84 [21]

$\sqrt{ \frac{-49}{(7-2i)-(4+9i) } } 
$

This one is quite the deal, but we can begin by distributing the negative on the denominator and getting rid of the parenthesis:

$\frac{ \sqrt{-49}}{7-2i-4-9i}$

See how the denominator now is more a simplification of like terms, with this I mean that you operate the numbers with an "i" together and the ones that do not have an "i" together as well. Namely, the 7 and the -4, the -2i with the -9i.
Therefore having the result:

$\frac{ \sqrt{-49} }{3-11i}$

Now, the $\sqrt{-49}$ must be respresented as an imaginary number, and using the multiplication of radicals, we can simplify it to $\sqrt{49} \sqrt{-1}$
This means that we get the result 7i for the numerator.

$\frac{7i}{3-11i}$

In order to rationalize this fraction even further, we have to remember an identity from the previous algebra classes, namely: $x^2 - y^2 =(x+y)(x-y)$
The difference of squares allows us to remove the imaginary part of this fraction, leaving us with a real number, hopefully, on the denominator.

$\frac{7i (3+11i)}{(3-11i)(3+11i)}$

See, all I did there was multiply both numerator and denominator with (3+11i) so I could complete the difference of squares.
See how $(3-11i)(3+11i)= 3^2 -(11i)^2$ therefore, we can finally write:

$\frac{7i(3+11i)}{3^2 - (11i)^2 }$

I'll let you take it from here, all you have to do is simplify it further.
The simplification is quite straightforward, the numerator distributed the 7i. Namely the product $7i(3+11i) = 21i+77i^2$ .
You should know from your classes that i^2 = -1, thefore the numerator simplifies to $-77+21i$
You can do it as a curious thing, but simplifying yields the result:
$\frac{-77+21i}{130}$

7 0

4 years ago

Julie decided to grow a plant from a seed. She measured the height of her plant each day for 30 days.

k0ka [10]

The given formula is f(t) = 0.4t

They want to solve for f(10), replace t in the formula with 10"

f(10) = 0.4(10)

Multiply:

f(10) = 4 centimeters.

4 0

4 years ago