the AP problem

Algebra Level 3

If the nth term of an AP is 7-4n then its common difference is

-3 4 -4 3

Achal Jain by Achal Jain , 19, India

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

2 solutions

Tapas Mazumdar
Mar 23, 2017

T n = 7 − 4 n T n + 1 = 7 − 4 ( n + 1 ) = 3 − 4 n ∴ d = T n + 1 − T n = ( 3 − 4 n ) − ( 7 − 4 n ) = − 4 T_n = 7 - 4n \\ T_{n+1} = 7 - 4(n+1) = 3 - 4n \\ \therefore d = T_{n+1} - T_n = (3-4n) - (7-4n) = \boxed{-4}

1 Helpful 0 Interesting 0 Brilliant 0 Confused
Tapan Saraph
Mar 29, 2015

tn=a+(n-1)d 7-4n=a+(n-1)d...........(1) Since nth term is 7-4n,for first term put n=1. hence a=3..........(2) Solving we get d=-4

0 Helpful 0 Interesting 0 Brilliant 0 Confused

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...