Find the sum of the infinite geometric series.

4-4/5+4/25-4/125 + ...

The formula for infinite geometric series is s=a1/1-r. If you would need to find your r, the ratio. The ration in this problem is - 1/5. We already know your a1, your first number. Plug everything in.

s = 4/1 - (-1/5)

s=4/1+1/5

s=4 / (6/5)

s=4*5/6 (multiplying the reciprocal is the same as dividing)

s=20/6

s = 3 1/3