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3 years ago

3/9=21/k what is the strategy for solving it

Mathematics

1 answer:

Vinvika [58]3 years ago

5 0

Answer: k = 63

Step-by-step explanation: You need to multiply the left side by its reciprocal to move the numbers to the right. You also need to multiply by k on the right side to get it alone on the left. This will result in

(9/3)(3/9) = (21/k)(9/3) simplified

1 = 189/3k • k then multiply by k

k = 189/3 simplify

k = 63

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I also need some help on this one. I need the area of the shaded region

givi [52]

What you have is, a circle inside an OCTAgon, OCTA=8 sides

so hmm get the area of the octagon, will include the area also of the circle,
then
get the area of the circle, and subtract it from the area of the octagon
what's left, is the "difference", or the shaded area

$\bf \textit{area of a regular polygon}\\\\
A=\cfrac{1}{4}\cdot n\cdot s^2\cdot cot\left( \frac{180}{n} \right)\qquad 
\begin{cases}
n=\textit{number of sides in the polygon}\\
s=\textit{length of one side}\\
\frac{180}{n}=\textit{angle in degrees}\\
----------\\
n=8\\
s=10
\end{cases}
$

$\bf \textit{area of a circle}\\\\
A=\pi r^2\qquad r=radius$

when taking the cotangent, make sure your calculator is in Degree mode, since the angle is in degrees

6 0

4 years ago

If A ⊂ B, then A ∩ B = A ∪ B. always sometimes or never

Lisa [10]

Sometimes. Proof:

Assume $A\subset B$ .

Let $a\in A\cap B$ , so that $a\in A$ and $a\in B$ . Then of course $a\in A\cup B$ , so $A\cap B\subseteq A\cup B$ .

Now let $a\in A\cup B$ , so that $a\in A$ *or* $a\in B$ . Since $A\subset B$ , if $a\in A$ then $a\in B$ , so that $a\in A\cap B$ . But if $a\in B$ , then $a\not\in A$ , so it's not always the case that $a\in A\cap B$ , and therefore in general $A\cup B\not\subseteq A\cap B$ .

6 0

3 years ago

Whats number one<br> ??????

disa [49]

Answer:

What's number one what......?

Step-by-step explanation:

5 0

3 years ago

Write a compound inequality for the following graph. -3 -2 2 3 6 7 8 0 -2 < 1 >5 O–25 0-2

Mademuasel [1]

First we see there are two extremes, two limits

-2 and 5

x is between them

BUT theres a difference , the point at left is black

the point at right is white rounded

this means x is equal or less than -2

and x is ONLY less than 5 , not equal

so this means the answer is the d option

7 0

2 years ago

Calculating vacation costs

docker41 [41]

Answer:

cheap

Step-by-step explanation:

corona virus have a great day (:

7 0

3 years ago