Question

Find the 15th term of the arithmetic sequence 3x-7,5x-9,7x-11,.....

Answer 1

Answer is 31 x - 35 that’s the answer

Answer 2

31x - 35

Explanation:

The n th term of an arithmetic sequence is

`a_(n)` = a₁ + (n - 1)d

where a₁ is the first term and d the common difference

d = 5x - 9 - (3x - 7) = 5x - 9 - 3x + 7 = 2x - 2 and a₁ = 3x - 7, thus

`a_(15)` = 3x - 7 + 14(2x - 2) = 3x - 7 + 28x - 28 = 31x - 35