The formulas:

Expand the expression:

Plug the values into the expression:
First divide both sides by 5. Then you get the answer. -0 or 0 I'm not sure tho
Answer:

Step-by-step explanation:
We are given;
A geometric sequence;
-2,10,-50
Required to determine the nth term
The nth term in a geometric sequence is given by the formula;

where
is the first term and r is the common ratio;
In this case;

r = 10 ÷ -2
= -5
Therefore;
To get the nth term in the given geometric sequence we use;

Thus, the nth term is 