Question

Which term to A P 5 ,2, -1,....= -85

Answer 1

Answer:

A.P.=5,2,-1,...,-85

t1=5,t2=2,t3=-1,....tn=-85

First term of an A.P=5

Common difference of an A.P.=d=t2-t1=2-5=-3

we know that,

nth term of an A.P

tn=a+(n-1)d

here,tn=-85,a=5,d=-3

-85=5+(n-1)-3

-85=5-3n+3

-85=8-3n

3n=8+85

3n=93

n=93/3

n=31.

Therefore, the 31st term of an A.P. is -85