Answer:
f(x) = 1.5x - 0.5x
Step-by-step explanation:
The function of the pattern represented by the pentagonal numbers is the sum of three triangular numbers.
The triangular number general formula
x (x + 1) / 2
For example,
The sequence
1, 3, 6, 10
*
* * *
* * * * * *
* , * *, * * *, * * * *
_____________________________
The pentagonal numbers
The sequence:
1, 5, 12, 22, 35
As shown in the picture can be divided into three triangles
Triangle 2
x (x + 1) / 2
Triangle 1 and 3 (they are triangles one unit smaller than 2)
n (n + 1) / 2
n= x-1
Replacing n
(x-1) ((x-1) + 1) / 2
(x-1) (x) / 2
(x-1) x / 2
______________
Function represents the pattern
Triangle 2 + (Triangle 1 + Triangle 3)
Triangle 1 = Triangle 3
So then,
Triangle 2 + 2* Triangle 1
x (x +1) /2 + 2* (x -1) x/2
Rearranging
0.5 x (x +1) + x(x -1)
0.5x^2 + 0.5x + x^2 -x
(0.5 x^2 + x^2) + (0.5x -x )
1.5 x^2 - 0.5 x
______
Answer:
1.36+3+(32)(2)
=57
error is that 6 is the wrong answer
Answer:
$51.12
Step-by-step explanation:
Hello there!
In number 19, we want to find the total price of a sweatshirt that costs $48 dollars but has 6.5% sales tax
Sales tax is a small percentage of the cost of an item that is added to items when they are being sold.
In this problem, 6.5% of the cost of the sweatshirt will be added to the cost of the sweatshirt in the form of sales tax. The price of the sweatshirt plus the amount in sales tax will be the total cost of the sweatshirt.
Translating that as an equation,
48 + 48*6.5%=total cost
You can calculate 48*6.5% as 
, which is equal to 3.12
So that means that $3.12 will be added to the cost of the sweatshirt.
Therefore,
48 + 3.12=<u>$51.12</u>, which will be the total cost of the sweatshirt, including sales tax
Hope this helps!
She should invest $6491.73.
The equation we use to solve this is in the form
,
where A is the total amount in the account, p is the principal invested, r is the interest rate as a decimal, n is the number of times per year the interest is compounded, and t is the amount of time.
A in our problem is 14000.
p is unknown.
r is 6% = 6/100 = 0.06.
n is 2, since it is compounded semiannually.
t is 13.
