13th term is 27 --- a + 12d = 27
the 7th iterm is 3 times the 2nd term --> a+6d = 3(a+d)
or
a+6d = 3a + 3d
2a = 3d
a = 3d/2
sub into the first equation
3d/2 + 12d = 27
3d+24d=54
d = 2
then a = 3(2)/2 = 3
I will let you finish it for the sum, you did not say how many terms you want to add.
in an arthmetic progression or series,the 13th term is 27 and the 7th iterm is 3 times the 2nd term ,find first term the common difference the sum of rhe squence
1 answer
1 answer