Given:
First term of an arithmetic sequence is 2.
Sum of first 15 terms = 292.5
To find:
The common difference.
Solution:
We have,
First term: 
Sum of first 15 terms: 
The formula of sum of first n terms of an AP is
![S_n=\dfrac{n}{2}[2a+(n-1)d]](https://tex.z-dn.net/?f=S_n%3D%5Cdfrac%7Bn%7D%7B2%7D%5B2a%2B%28n-1%29d%5D)
Where, a is first term and d is common difference.
Putting , n=15 and a=2 in the above formula, we get
![292.5=\dfrac{15}{2}[2(2)+(15-1)d]](https://tex.z-dn.net/?f=292.5%3D%5Cdfrac%7B15%7D%7B2%7D%5B2%282%29%2B%2815-1%29d%5D)
![292.5=\dfrac{15}{2}[4+14d]](https://tex.z-dn.net/?f=292.5%3D%5Cdfrac%7B15%7D%7B2%7D%5B4%2B14d%5D)
![292.5=15[2+7d]](https://tex.z-dn.net/?f=292.5%3D15%5B2%2B7d%5D)
Divide both sides by 15.
Dividing both sides by 7, we get
Therefore, the common difference is 2.5.
Answer:
22 and 7
Step-by-step explanation:
Let x and y be the two numbers we are looking for:
The statement “their sum is 29” means x + y = 29
The statement “their difference is 15” means x - y = 15
we get this system:
x + y = 29 (1)
x - y = 15 (2)
Let’s solve it :
(1) + (2) ⇒ x + y + x - y = 29 + 15 ⇒ 2x = 44 ⇒ x = 44/2 = 22
Now we replace x by 22 in equation (1) :
22 + y = 29 ⇒ y = 29 - 22 = 7
Answer: R12.20
Step-by-step explanation:
VAT in South Africa is 15% so if the flat rate is R93.57, the VAT amount can be found by finding the pre-tax flat rate:
93.57 = x + 0.15x
1.15x = 93.57
x = 93.57/1.15
x = R81.37
VAT is 15% of R81.37:
= 15% * 81.37
= R12.20
Answer:
i think its 63
3:4
84 divided by 4 equals 21, so then you multiply 3 by 21 and get 63
Answer:
m = 0.75
Step-by-step explanation:
16 x 2m = 4x8 - 8
32m = 24
m = 24/32
