Step-by-step 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
[tex]\boxed{\sf a_n=a+(n-1)d}[/tex]
[tex]\\ \:\:\:\:\sf {:}\dashrightarrow a_{26}=-15+(26-1)(-20)[/tex]
[tex]\\ \:\:\:\:\sf {:}\dashrightarrow a_{26}=-15+25(-20)[/tex]
[tex]\\ \:\:\:\:\sf {:}\dashrightarrow a_{26}=-15+(-500)[/tex]
[tex]\\ \:\:\:\:\sf {:}\dashrightarrow a_{26}=-15-500[/tex]
[tex]\\ \:\:\:\:\sf {:}\dashrightarrow {\boxed{\bf a_{26}=-515}}[/tex]
