Question

find the sum of 25th term and ​

Answer 1

Answer:

-800

Step-by-step explanation:

n = 1,

a1= 7-3

=4

a25 =

$7 - 3 \times 25 \\ = 7 - 75 \\ = - 68$

sn =

$\frac{25}{2} (4 + - 68) \\ 25 \times - 32 = - 800$