Answer:
55 Rs.
Step-by-step explanation:
cost of the milk:
15.5 x 30 = 465 Rs.
Gross sales of the milk:
26 x 20 = 520 Rs.
Profit:
520 - 465 = 55 Rs.
Rita spent 20$. By multiplying 5 pairs with 4$ we can see that it will equal 20$
Answer:Answer:
Step-by-step explanation:
Given the sequence -4,-6,-8..., in order to get sigma notation to represent the sum of the first seven terms of the sequence, we need to first calculate the sum of the first seven terms of the sequence as shown;
The sum of an arithmetic series is expressed as ![S_n = \frac{n}{2}[2a+(n-1)d]](https://tex.z-dn.net/?f=S_n%20%3D%20%5Cfrac%7Bn%7D%7B2%7D%5B2a%2B%28n-1%29d%5D)
n is the number of terms
a is the first term of the sequence
d is the common difference
Given parameters
n = 7, a = -4 and d = -6-(-4) = -8-(-6) = -2
Required
Sum of the first seven terms of the sequence
![S_7 = \frac{7}{2}[2(-4)+(7-1)(-2)]\\\\S_7 = \frac{7}{2}[-8+(6)(-2)]\\\\S_7 = \frac{7}{2}[-8-12]\\\\\\S_7 = \frac{7}{2} * -20\\\\S_7 = -70](https://tex.z-dn.net/?f=S_7%20%3D%20%5Cfrac%7B7%7D%7B2%7D%5B2%28-4%29%2B%287-1%29%28-2%29%5D%5C%5C%5C%5CS_7%20%3D%20%20%5Cfrac%7B7%7D%7B2%7D%5B-8%2B%286%29%28-2%29%5D%5C%5C%5C%5CS_7%20%3D%20%20%5Cfrac%7B7%7D%7B2%7D%5B-8-12%5D%5C%5C%5C%5C%5C%5CS_7%20%3D%20%5Cfrac%7B7%7D%7B2%7D%20%2A%20-20%5C%5C%5C%5CS_7%20%3D%20-70)
The sum of the nth term of the sequence will be;
![S_n = \frac{n}{2}[2(-4)+(n-1)(-2)]\\\\S_n = \frac{n}{2}[-8+(-2n+2)]\\\\S_n = \frac{n}{2}[-6-2n]\\\\S_n = \frac{-6n}{2} - \frac{2n^2}{2}\\S_n = -3n-n^2\\\\S_n = -n(3+n)](https://tex.z-dn.net/?f=S_n%20%3D%20%5Cfrac%7Bn%7D%7B2%7D%5B2%28-4%29%2B%28n-1%29%28-2%29%5D%5C%5C%5C%5CS_n%20%3D%20%5Cfrac%7Bn%7D%7B2%7D%5B-8%2B%28-2n%2B2%29%5D%5C%5C%5C%5CS_n%20%3D%20%5Cfrac%7Bn%7D%7B2%7D%5B-6-2n%5D%5C%5C%5C%5CS_n%20%3D%20%20%5Cfrac%7B-6n%7D%7B2%7D%20-%20%20%5Cfrac%7B2n%5E2%7D%7B2%7D%5C%5CS_n%20%3D%20-3n-n%5E2%5C%5C%5C%5CS_n%20%3D%20-n%283%2Bn%29)
The sigma notation will be expressed as . <em>The limit ranges from 1 to 7 since we are to find the sum of the first seven terms of the series.</em>
First you want to get x by it’s self so you need to get ride of your 5 so you subtract 5 on both sides leaving you with -2 and -5 on the same side then you combine those two number to get -7 now to get your x all you have to do is divide both sides by -7 since your x is -7 once once your x is now by its self but on the other side -7 divided by -7 equals 1 bc 7 goes into 7 once and it turns positive because anytime you divide an negative number by a negative number it turns into a positive number so your answer over all is 1=x
