Question

which term of AP is first positive term -9,-8.25,-7.5
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Answer 1

Explanation

In this a.p series,

a = -9

d = (-7.5)-(-8.25) = 0.75

so, the first positive value will = 0 + 0.75 = 0.75

now we have to find out, that which term of this a.p series will 0.75

we know,

tn = a + (n-1)×d

here tn = 0.75, a = -9, d = 0.75 , n=?

find n.

put the values we get

0.75 = (-9) + (n-1)× 0.75

=> (n-1)× 0.75 = 9.75

=> n= (9.75/0.75) + 1

=> n = 13 + 1

=> n = 14

so, the first positive term will 14th term.