Question

find first term...plz urgent ​

Answer 1

Let first term of A.P be ' a '

Common difference be ' d'

Then, as given

Tenth term = a + 9d = 25 _______eqn 1

And

Eighteenth term= a+17d = 11 ___

___eqn 2

Subtracting eqn 1 from eqn 2

a+17d - a - 9d = 11-25

8d = -14

d = -14/8

d = -7/4

Putting value of d in eqn 1

a + 9d = 25

a = 25 -9d

a= 25 - 9×(-7/4)

a= 163/4

SO THE FIRST TERM WILL BE 163/4

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