Answer:
She has 20 coins in her bank, where she has 12 nickels and 8 quarters
Step-by-step explanation:
- A nickel is 5 cents
- Since she has 8 fewer than nickels, we add 8 to the number of nickels
Q = N + 8, 25Q + 5N = 560
25(N + 8) + 5N = 560
25N + 200 + 5N = 560
25N + 200 - 200 + 5N = 560 - 200
30N = 360
30N / 30 = 360 / 30
N = 12 nickels
Finding amount of Quarters:
Q = N + 8 → Q = 12 + 8
Q = 20 quarters
Learn more about System of Linear Equations here: brainly.com/question/2226590
Answer:
Step-by-step explanation:
The identities you need here are:
and 
You also need to know that
x = rcosθ and
y = rsinθ
to get this done.
We have
r = 6 sin θ
Let's first multiply both sides by r (you'll always begin these this way; you'll see why in a second):
r² = 6r sin θ
Now let's replace r² with what it's equal to:
x² + y² = 6r sin θ
Now let's replace r sin θ with what it's equal to:
x² + y² = 6y
That looks like the beginnings of a circle. Let's get everything on one side because I have a feeling we will be completing the square on this:
Complete the square on the y-terms by taking half its linear term, squaring it and adding it to both sides.
The y linear term is 6. Half of 6 is 3, and 3 squared is 9, so we add 9 in on both sides:
In the process of completing the square, we created within that set of parenthesis a perfect square binomial:
And there's your circle! Third choice down is the one you want.
Fun, huh?
The water temperature at the beach was 75° every day for the past<span>2 weeks. The water temperature at the beach will be 75° today. All even numbers are divisible by 2. Sixty-four is an even number. Sixty-four is divisible by 2.
others are deductive reasoning
</span>The library charges a $0.20 fine each day a book is overdue. Mary is returning a book that is 5 days overdue. Therefore, Mary will pay a $1.00 fine. All observed brown dogs are small dogs. Therefore, all small dogs are brown.
<span>
</span>
Answer:
isn't an equivalence relation. It is reflexive but neither symmetric nor transitive.
Step-by-step explanation:
Let 
denote a set of elements. 
would denote the set of all ordered pairs of elements of 
.
For example, with 
, 
and 
are both members of . However, 
because the pairs are ordered.
A relation on is a subset of . For any two elements
, 
if and only if the ordered pair 
is in 
.
A relation on set is an equivalence relation if it satisfies the following:
- Reflexivity: for any
, the relation needs to ensure that 
(that is: 
.)
- Symmetry: for any , if and only if
. In other words, either both and 
are in , or neither is in .
- Transitivity: for any
, if and 
, then 
. In other words, if and 
are both in , then 
also needs to be in .
The relation (on ) in this question is indeed reflexive. 
, 
, and 
(one pair for each element of ) are all elements of .
isn't symmetric. 
but 
(the pairs in 
are all ordered.) In other words, 
isn't equivalent to 
under even though 
.
Neither is transitive. 
and 
. However, . In other words, under relation , 
and 
does not imply 
.
