ANSWER
[tex]a_n=a_{n-1} - 13.8 \: where \: \: a_1 = - 7.4[/tex]
EXPLANATION
The given sequence is
-7.4, -21.2,-35,-48.8,-62.6,...
The first term of this sequence is
[tex]a_1=-7.4[/tex]
The constant difference can be calculated using any two consecutive terms:
[tex]d = - 35 - - 21.2 = - 13.8[/tex]
The recursive rule is given by;
[tex]a_n=a_{n-1}+d[/tex]
We plug in the values to get,
[tex]a_n=a_{n-1} + - 13.8[/tex]
[tex]a_n=a_{n-1} - 13.8 \: where \: \: a_1 = - 7.4[/tex]
The correct choice is A.
