what is the explicit formula for this sequence -1,4,-16,64

Answer:
The answer is c.
Step-by-step explanation:
[tex]a_{1} =-1*(-4)x^{n-1}[/tex]
[tex]a_{1} =-1(-4)^{1-1}[/tex]
[tex]a_{1} =-1(-4)^{2} \\a_{1} =-1(1)\\a_{1} =-1[/tex][tex]a_{2} =-1(-4)^{2-1} \\a_{2} =-1(-4)^{1} \\a_{2} =-1(-4)\\a_{2}=4[/tex][tex]a_{3}=-1(-4)^{3-1} \\a_{3}=-1(-4)^{2} \\a_{3}=-1(16)\\a_{3}=-16[/tex]