These questions still confuse me greatly for some reason. i got the formula for it but i still don't know how to use it. , could someone explain it for me! write an equation for the nth term of the geometric sequence 896, -448, 224, find the eighth term of this sequence.

The first term is 896.
The common ratio is -448/896 = -1/2.

The formula tells you the n-th term (an) is
.. an = a1*r^(n-1)
As with any formula, you substitute the given values to find the one you want to know.
.. a8 = 896*(-1/2)^(8 -1) = -896/128 = -7

Even if you don't know how to do the arithmetic, your calculator does.

The eighth term of the sequence is -7.

It is 5.8 you add all of the up to equat 180 then solve the equation