Find a geometric series with the sum of 4. explain your process.

I know that 1/2+1/4+1/8+1/16+... will equal 1

1/2*2 =1

1*2 =2

2+1= 3

if you continue that series, then you get
2+1+1/2+...
2+1+1 =4

Though a more formal way would be something along the lines of



pick a random a0, and then just solve for r