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
![S_n= \frac{n}{2} [2a_1+(n-1)d]S](https://tex.z-dn.net/?f=S_n%3D%20%5Cfrac%7Bn%7D%7B2%7D%20%5B2a_1%2B%28n-1%29d%5DS)
.
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.
Answer:
X= -3/2
Step-by-step explanation:
6x/6=-9/6
Answer:
14
Step-by-step explanation:
you clean 2 a hour so 7*2=14
Answer: x=-30
Step-by-step explanation: -1/5x(-5)=6(-5) x=-30
Jeff received 280$ from his mother
Such questions are the simplest as it needs you to just write the conditions accordingly which then simplifies and provides you the answer.
This question can be solved using two tricks which are shown below:-
Trick 1 :
1 – 1/4 = 3/4 (used for the 1st 7 days)
1/4 – 410 (used for 8th and 9th days)
(3/4)/7 ——- (1/4 – 10)/2
(3/4) x (2/7) = 3/14 ——- (1/4 – 10)
1/4 – 3/14 = (7 – 6)/28 = 1/28 ——- 10
28/28 ——- 10 x 28 =$ 280
Trick 2 :
7 days ——- 3/4
1 day ——- 3/28
2 days ——- 6/28
6/28 ——- (1/4 – 10) = 7/28 – 410
1/28 ——- 10
28/28 ——- 10 x 28 = $280
Thus Jeff received 280$ from his mother.
Learn more about simple math here :
brainly.com/question/23678
#SPJ4
