Question

12+19+26+.......+558 का योग ज्ञात कीजिए।
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Answer 1

Answer:

an =a 1 +(n−1)d ap series h

Step-by-step explanation:

The sum of the members of a finite arithmetic progression is called an arithmetic series.

Using our example, consider the sum:

12+19+26+33+40+47+54+61

This sum can be found quickly by taking the number n of terms being added (here 8), multiplying by the sum of the first and last number in the progression (here 12 + 61 = 73), and dividing by 2:

n(a1+an)

2

8(12+61)

2

The sum of the 8 members of this series is 292

This series corresponds to the following straight line y=7x+12

Answer 2

Step-by-step explanation:

558=12+(n-1)7

(n-1)=546/7

(n-1)=78

n=79

Sn=79/2(2×12+78×7)

=79/2(570)

=79×285

=22515