Can someone me and explain step by step

 5) r = 5, 8th term = -78,125

               6) r = 5, 8th term = -312,500

               7) r = 5, {1, 5, 25, 125, 625}

               8) r = 5, {-4, -20, -100, -500, -2500}

Step-by-step explanation:

The explicit formula of a geometric sequence is: , where;

step-by-step explanation:

what grade level is this? need to know so i can look in my old textbooks!