Question

the 6th term of an A.P is -10 and 10th term is -26.Find the first term and common difference​

Answer 1

SOLUTION

* 6th term is -10

so, a+ 5d= -10...........(1)

* 10th term is -26

so, a+9d= -26..............(2)

solving (1) &(2), we get

=) a+9d= -26

a+5d= -10

- - +

_______________

=) 4d= -16

=) d= -16/4

=) d= -4.............(3)

Putting (3) in equation (1)

=) a+5d= -10

=) a+5(-4)= -10

=) a+ (-20)= -10

=) a-20= -10

=) a= -10+20

=) a= 10

So,

a= 10 and d= -4

hope it helps