Step-by-step explanation:
the sequence is arithmetic due to the common difference that is equal
d=11-15=7-11=-4
a(n) = a1 +(n-1)d
a1=15
Then :
a(n) = 15+(n-1)-4
hope this helps
Answer:
200 cm
Step-by-step explanation:
2*100= 200
for question 1
Area of Base B =45×25 = 1125 cm²
perimeter of base P = 2(45+25) = 140 cm
Height = 15 cm
Using the formula
Surface area = 2B + Ph
A = 2×1125 + 140×15= 4350 cm²
Voume = Bh = 1125×15= 16875 cm³
For question 2,
Area of base = 7× 5/2= 17.5 cm²
Perimeter of base = (7+7+7) = 21 cm
Surface area = 2B + Ph
Surface area of prism = 2×17.5+ 21×10 = 245cm²
Volume = Bh = 17.5×10 = 175 cm³
You would recieve $37.95 a year then multiply that by 7 years to get $265.65
Answer:
8428
Step-by-step explanation:
According to the Question,
- Given, A theater has 56 rows of seats. If there are 13 seats in the first row, 18 in the 2nd row, 23 in the 3rd row.
We have a number sequence 13, 18, 23, ...
- We can say that this is an arithmetic sequence because of the common difference 'd', is equal to 5, and the first term 'a1' is equal to 13.
- The formula for the sum of an arithmetic sequence with n terms is given is
.
Substitute the given values into the equation to solve for the sum of the 56 rows of seats.
![S_56= \frac{56}{2}[2(13)+(56-1)(5)]\\S_{56}=28\left[26+275\right]\\S_{56}=28\left[301\right]\\S_{56}=8428](https://tex.z-dn.net/?f=S_56%3D%20%5Cfrac%7B56%7D%7B2%7D%5B2%2813%29%2B%2856-1%29%285%29%5D%5C%5CS_%7B56%7D%3D28%5Cleft%5B26%2B275%5Cright%5D%5C%5CS_%7B56%7D%3D28%5Cleft%5B301%5Cright%5D%5C%5CS_%7B56%7D%3D8428)
Therefore, there are 8428 seats in all.