Find an equation for the nth term of the sequence.
-1, -4, -16, -64, ...

An =4^(n-1)

Step-by-step explanation:

hello :

the sequence is geometric because : (-64)/(-16) = (-16)/(-4)=-4/-1= 4=r

the nth term is :  An =A1 × r^(n-1)

a common ratio is : r  and A1 the first term

in this exercice :   r =4        A1 = 1

An =A1 × r^(n-1)

An =1 × 4^(n-1)=4^(n-1)

step-by-step explanation: