Question

The 7th team of an arithematic sequence is 44 and the 13th team is 80. find the sum of the first 19 term?​

Answer 1

Answer:

gw ko yah ek bahut bada yogdan raha h pura pani

Answer 2

Answer:

1,178

Step-by-step explanation:

HAVE TO FIND THE SUM OF FIRST 19 TERMS

 

WE HAVE 7'TH TERM = 44-------------(1)

               13'TH TERM = 80-----------(2)

     ⇒      a + 6d = 44-------------------(1)

              a + 12d = 80-------------------(2)

                    -6d = -36

                ⇒ d = 6

a + 6d = 44

a + 36 = 44

a = 8

FIRST TERM = 8

19'TH TERM = A + 18D ⇒ 8 + 108 = 116

19'TH TERM = 116

SUM OF FIRST 19 TERMS = $\frac{n}{2}(a + l)\\\\\frac{19}{2}(8 + 116)\\\\\frac{19}{2}(124)\\\\sum = 1,178$