Question

(vii) given a = 4, d = 2, S = -14, find n and a​

Answer 1

$\huge\star\bold\red{ANSWER}$

$\star\bold\red{Given:-}$ a=4,d=2,Sn=-14

$\star\bold\red{To}$$\bold\red{Find:-}$ n=?,a=?

$\star\bold\red{Solution:-}$

=>Sn=-14

=>$\frac{n}{2}$[2a+(n-1)d]=-14

=>$\frac{n}{2}$[2×4+(n-1)2]

=>$\frac{n}{2}$[8+(2n-2)]

=>$\frac{n}{}$(6+2n)=-14×2

=>6n+2n=-28

=>8n=-28

=>n=$\frac{-28}{8}$

=>$\frac{-14}{4}$ $\bold\red{....ans....}$

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