Answer:
![3^{n}+3^{n-1}](https://tex.z-dn.net/?f=3%5E%7Bn%7D%2B3%5E%7Bn-1%7D)
Step-by-step explanation:
Since the sequence is geometric (it multiplies the previous number each time). The nth term sequence would be ![x^n + yn](https://tex.z-dn.net/?f=x%5En%20%2B%20yn)
Because the sequence multiplies by 3 each time, The base number in that equation would be
.
So
of the equation would be:
.
Compare the 2 equations:
4, 12, 36
3, 9 ,27
The difference between the 2 equations is: 1, 3, 9 which itself is a geometric sequence so the nth term of this new equation is:
.
Combine these 2 equations together and you get:
.
(Y+4)(y+2) is this what it supposed to look like? Cause I don’t really remember.
The number of kids in your group is 12.
Step-by-step explanation:
Given,
Number of people = 20
Cost of each kid ticket = $4
Cost of each adult ticket = $6
Total spent = $96
Let,
x be the number of kids ticket
y be the number of adult ticket
According to given statement;
x+y=20 Eqn 1
4x+6y=96 Eqn 2
Multiplying Eqn 1 by 4
![4(x+y=20)\\4x+4y=80\ \ \ Eqn\ 3](https://tex.z-dn.net/?f=4%28x%2By%3D20%29%5C%5C4x%2B4y%3D80%5C%20%5C%20%5C%20Eqn%5C%203)
Subtracting Eqn 3 from Eqn 2
![(4x+6y)-(4x+4y)=96-80\\4x+6y-4x-4y=16\\2y=16](https://tex.z-dn.net/?f=%284x%2B6y%29-%284x%2B4y%29%3D96-80%5C%5C4x%2B6y-4x-4y%3D16%5C%5C2y%3D16)
Dividing both sides by 2
![\frac{2y}{2}=\frac{16}{2}\\y=8](https://tex.z-dn.net/?f=%5Cfrac%7B2y%7D%7B2%7D%3D%5Cfrac%7B16%7D%7B2%7D%5C%5Cy%3D8)
Putting y=8 in Eqn 1
![x+8=20\\x=20-8\\x=12](https://tex.z-dn.net/?f=x%2B8%3D20%5C%5Cx%3D20-8%5C%5Cx%3D12)
The number of kids in your group is 12.
Keywords: linear equation, elimination method
Learn more about elimination method at:
#LearnwithBrainly
For the first letter we have 24 choices. Since letters can't repeat the second letter has 23 choices (24 minus 1 that was used for the first slot) and the third has 22 (24 minus one for the first slot and one for the second slot).
The total number of combinations is thus: 24 x 23 x 22= 12,144