For fun questionfind the formula for how many items are in a 2 deimentional pyramid (each row is 1 more than previous row like in attachment) when you have n number of rows

n=number of rows
n,x means when you have n rows, you have x items in pyramid

n=1, 1
n=2, 3
n=3, 6
n=4, 10
n=5, 15

find the number of items when you have n number of rows
f(n)=something

SHOW ALL WORK AND LOGIC
NO GOOGLING TO FIND ANSWER OR JUST PUTTING THE ANSWER

Answers

Answer 1

Answer: We have an arithmetic progression:
an=number of item at row n

an=a₁+(n-1)d

d=common difference=an-a(n-1)=a₂-a₁=2-1=1
n=number of row

In this case:

an=1+(n-1)*1=n

The sum of an arithmetic serie is:
Sn=(a₁+an)n / 2

In this case:
a₁=1 (number of itms in the first row)
an=n (we have to calculate this before)

Sn=(1+n)n /2=(n+n²)/2

Therefore:
f(n)=Sn=number of items when we have n number of rows

f(n)=(n+n²)/2

Answer: f(n)=(n+n²)/2

To chek:

f(1)=(1+1²)/2=1
f(2)=(2+2²)/2=6/2=3
f(3)=(3+3²)/2=(3+9)/2=12/2=6
....

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If you make an annual salary of $18,920, what is the maximum monthly rent you can afford?$529.76

$441.47

$882.94

$536.22

Answers

If you make an annual salary of $18,920, Find the maximum monthly rent you can afford:
=> 18 920 dollars / 12 months = 1576.67 dollars is your monthly payment.
Base on the given choices, you can afford all prices but practicality wise, 441.47 dollars is the most recommended rentals.

Answer with explanation:

We will use , $(28)/(36)$ rule here, which states that , 28 % of your monthly income should be used for housing finances and 36 % of your total gross income should be used for debt purposes.

Total Annual Salary = $ 18,920

Monthly salary $=(18920)/(12)$

→→28% of 18,920

$=(28)/(100)* (18920)/(12)\n\n=(529760)/(100* 12)=441.4666\n\n=441.47$

Option B: $ 441.47

What is the arc length when θ = and the radius is 7 cm? (5 points)

Answers

What is the arc length when Θ=3 pi/5 and the radius is 7 cm?
Here are the available answers... 21pi/5 cm 12pi/5 cm 6pi/5 cm 3pi/35 cm

Given:
arc length = theta * radius
arc length = (3 pi/5)(7cm)
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If 2x=4 what is the value of x

Answers

Please try to follow my steps carefully.

2x = 4

Divide each side of the equation by 2:

x = 2

if 2x=4
then
x=4/2
x=2
hence the value of x is 2

PLSS help

the answer either has to be -3 , 1/2, 2, 3, 0 , 1 , -2 , 5 , undefined

Answers

Answer:

-3

Step-by-step explanation:

4-7/1-0

1-4/2-1

-2-1/3-2

Can you please help me with this question.

Answers

The answer is B
Hope this helped

The answer is "B". You have 20 coins and d represents the amount of dimes and q, the amount of quarters. Therefore, q+d = 20. Also the value of dimes is equal to .1 times the number of dimes. Value of quarters is equal to .25 times the amount of quarters. Therefore, .1d + .25q = 4.25

Anna runs three over4 mile in six minutes. Assuming she runs at a constant rate what is her speed in miles per hour

Answers

Answer:

7.5 mph

Step-by-step explanation:

6 times 10 is 60 minutes which is an hour

3/4 times ten is 7.5