Respuesta :

1365kokila

[tex] - 13 + ( - 3) = - 16 \\ - 16 + ( - 3) = - 19 \\ - 19 + ( - 3) = - 22 \\ - 22 + ( - 3) = - 25[/tex]
you have to plus (-3) for each numbers

Answer:

[tex]a_n =-3n-10[/tex]

Step-by-step explanation:

-13 + (-16) + (-19) +...

Difference between two terms = -3

-16 -(-13)= -3

-19 -(-16)= -3

Common difference is a constant so it is arithmatic

[tex]a_n = a_1+(n-1)d[/tex]

where 'd' is the difference = -3

a1 is the first term that is -13

[tex]a_n = -13+(n-1)(-3)[/tex]

[tex]a_n = -13-3n+3[/tex]

Combine like terms

[tex]a_n =-3n-10[/tex]