First term ,a=4 , common difference =4-7=-3, n =50
sum of first 50terms= (50/2)[2×4+(50-1)(-3)]
=25×[8+49]×-3
=25×57×-3
=25× -171
= -42925
derivation of the formula for the sum of n terms
Progression, S
S=a1+a2+a3+a4+...+an
S=a1+(a1+d)+(a1+2d)+(a1+3d)+...+[a1+(n−1)d] → Equation (1)
S=an+an−1+an−2+an−3+...+a1
S=an+(an−d)+(an−2d)+(an−3d)+...+[an−(n−1)d] → Equation (2)
Add Equations (1) and (2)
2S=(a1+an)+(a1+an)+(a1+an)+(a1+an)+...+(a1+an)
2S=n(a1+an)
S=n/2(a1+an)
Substitute an = a1 + (n - 1)d to the above equation, we have
S=n/2{a1+[a1+(n−1)d]}
S=n/2[2a1+(n−1)d]
Answer:
1, 3, & 5
Step-by-step explanation:
Select three options.
1. The inequality should be written as 25 s less than 300.
2. The inequality should be written as 25 s greater than 300.
3. The circle is open.
4. The circle is closed.
5. The arrow points left.
I'm guessing these are the options? If so, please mark brainliest :)
Alright, lets get started.
Suppose total number of dancers in school = x
We have given in question, 42 % of total dancers are ballet dancers.
So, we could find number of ballet dancers by finding 42 % of total dancers.
Number of ballet dancers = x * 42 %
Number of ballet dancers = x * 42/100 = 0.42 x
As per given in question, there are 63 ballet dancers in school.
Which means 0.42 x = 63
Dividing 0.42 from both sides
0.42 x / 0.42 = 63 / 0.42
x = 150
Hence number of total dancers in school = 150 : Answer
Hope it will help :)
Step-by-step explanation:
Las organizaciones son estructuras administrativas y sistemas administrativos creadas para lograr metas u objetivos con el apoyo de las propias personas, o con apoyo del talento humano o de otras características similares.
Answer:
SSS
Step-by-step explanation:
I can identify that these triangles are congruent by using the SSS (Side, Side, Side) postulate theorem. I know this because first, second, and home triangle share the same side as the third, second, and home triangle, meaning they are congruent, so are the other sides of the angle since the question states they are congruent.
