SOLUTION: Find the 6th and 15th term of the A.P whose first is 6 and common difference is 7

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Question 1176510: Find the 6th and 15th term of the A.P whose first is 6 and common difference is 7
Found 2 solutions by MathLover1, Boreal:
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
In General we could write an arithmetic sequence like this:
{ a, a%2Bd, a%2B2d, a%2B3d, ... }

and formula for nth term

a%5Bn%5D=a%5B1%5D%2Bd%28n-1%29 where n is the number of a term

if given +a%5B1%5D=6 and +d=7

6th term will be
a%5B6%5D=6%2B7%286-1%29
a%5B6%5D=6%2B7%285%29
a%5B6%5D=41

and 15th term will be
a%5B15%5D=6%2B7%2815-1%29
a%5B15%5D=6%2B7%2814%29
a%5B15%5D=104


Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
an=a1+(n-1)d
a6=6+(5)(7)=41
a15=6+(14)(7)=104
6
13
20
27
34
41
ten more terms is a16=111
a15 is 111-7=104