Enter a recursive rule for the geometric sequence. 10, −80, 640, −5120, ...a(1)=a(n)=

The recursive formula would be:
[tex]a_1=10 \\a_{n}=a_{n-1} \times (-8)[/tex]

This is because the first term, a₁, is 10.  A recursive rule is dependent upon the term before it (a(n-1)) and the common ratio.  The common ratio, or the number that each term is multiplied by, is -8.