Question

The first term of an ap is -7 and the common difference is 5 find its 18th term and general term

Answer 1

this answer may be help full to you.
general term
an=-12+5n

Answer 2

Answer:

The 18th term is 78 and the general term is  $a_n= -12+5n$

Step-by-step explanation:

First term = a = -7

Common difference = d= 5

Formula of nth term :$a_n=a+(n-1)d$

So, general term of A.P. = $a_n= -7+(n-1)5$

                                        = $a_n= -7+5n-5$

                                        = $a_n= -12+5n$

Thus the general term of given A.P. =  $a_n= -12+5n$

Now to find 18th term

Substitute n = 18 in general term

$a_{18}= -12+5(18)$

$a_{18}= 78$

Hence the 18th term is 78 and the general term is  $a_n= -12+5n$