Question

Find the a26 arithmetic sequence: -15,-35,-55,-75
-515
460
-490

Answer 1

Explanation:

QUESTION:-

Find 26th term of the A.P --15,-35,-55,-75...

Solution:-

First term=a=-15

Common Difference=d=-20

We know that

`\boxed{\sf a_n=a+(n-1)d}`

`\\ \:\:\:\:\sf {:}\dashrightarrow a_(26)=-15+(26-1)(-20)`

`\\ \:\:\:\:\sf {:}\dashrightarrow a_(26)=-15+25(-20)`

`\\ \:\:\:\:\sf {:}\dashrightarrow a_(26)=-15+(-500)`

`\\ \:\:\:\:\sf {:}\dashrightarrow a_(26)=-15-500`

`\\ \:\:\:\:\sf {:}\dashrightarrow {\boxed{\bf a_(26)=-515}}`