We have the formula a+(n-1)d=nth term
Where a is the 1st term ,d is the difference and n is the nth term
So1st term= a
2nd term= (a+1)d
3rd term= (a+2)d
Adding ad+2d+ad+ 4d= 38
2ad+ 6d= 38
In the same way 7th term=(a+6)d
Adding these 2ad+15d=83
Subtracting, 9d= 45 which makes d=5
a+2d + a+4d=38 -->2a + 6d = 38
a+6d + a+9d = 83 --> 2a + 15d = 83
9d = 45
back in 2a+6d = 38
the sequence is:
4 9 14 19 24 ...
BTW, the definitions used by Praphul are not correct.
e.g. he said:
5th term is (a+4)d
that should have been a + 4d, the brackets there are critical
Answer this Question
Mathematics - The sum of the 1st and 2nd terms of an AP is 4 and the 10th term ...
maths - the sum of the 4th and 6th terms of an A.P is 42. the sum of the 3rd and...
10th math - The sum of the 4th and 8th terms of an AP is 24 and the sum of the ...
Math - 1) If the sum of the first n terms of a series is Sn where Sn=2nē-n, (a)...
math - 1) If the sum of the first n terms of a series is Sn where Sn=2nē-n, (a)...
Geometric - 1) The sum of last three terms of GP having n terms is 1024 time the...
Math - Sum of4th and the 6th terms of an a,p is 42 . While the sum of the 3rd ...
maths - the sum of the first two terms of a GP is 28,but the sum of the third ...
Math *URGENT - Please give the answers and solutions for each. 1.If the second ...
Further mathematics - An exponential sequence (GP)of positive terms and a linear...