Answer:???
Step-by-step explanation:
Answer:
Online is cheaper by $2 if I did my math right. Online is $72 and the store is $74
Step-by-step explanation:
Answer:
9x+20>=28
Step-by-step explanation:
x is the number
I don't know if I did it right but here's my guess. I think you multiply 7 by 20% and that gives you 1.40 as a result. Compared to the other method I used (division), I'm pretty sure I'm right since the other result was 35. Doesn't make sense if the end amount was $7.
There's a fixed difference of 6 between terms (9 - 3 = 6, 15 - 9 = 6, and so on). The first term of the sequence is 3, so the
-th term is
![3 + 6(n-1) = 6n - 3](https://tex.z-dn.net/?f=3%20%2B%206%28n-1%29%20%3D%206n%20-%203)
If there are 24 terms in the sum, then the last term is 6×23 - 3 = 135.
Let
be the sum,
![S = 3 + 9 + 15 + \cdots + 123 + 129 + 135](https://tex.z-dn.net/?f=S%20%3D%203%20%2B%209%20%2B%2015%20%2B%20%5Ccdots%20%2B%20123%20%2B%20129%20%2B%20135)
Reverse the order of terms:
![S = 135 + 129 + 123 + \cdots + 15 + 9 + 3](https://tex.z-dn.net/?f=S%20%3D%20135%20%2B%20129%20%2B%20123%20%2B%20%5Ccdots%20%2B%2015%20%2B%209%20%2B%203)
If we add up the terms in the same positions, we get twice
on the left side, while on the right side we observe that each pair of terms will sum to 138.
![S + S = (3 + 135) + (9 + 129) + (15 + 123) + \cdots + (135 + 3)](https://tex.z-dn.net/?f=S%20%2B%20S%20%3D%20%283%20%2B%20135%29%20%2B%20%289%20%2B%20129%29%20%2B%20%2815%20%2B%20123%29%20%2B%20%5Ccdots%20%2B%20%28135%20%2B%203%29)
![2S = 138 + 138 + 138 + \cdots + 138](https://tex.z-dn.net/?f=2S%20%3D%20138%20%2B%20138%20%2B%20138%20%2B%20%5Ccdots%20%2B%20138)
and since there are 24 terms in the sum, the right side is the sum of 24 copies of 138. In other words,
![2S = 24 \times 138](https://tex.z-dn.net/?f=2S%20%3D%2024%20%5Ctimes%20138)
and solving for
gives
![S = \dfrac{24\times138}2 = \boxed{1656}](https://tex.z-dn.net/?f=S%20%3D%20%5Cdfrac%7B24%5Ctimes138%7D2%20%3D%20%5Cboxed%7B1656%7D)