`f) 1/(1.2) + 1/(2.3) + ... + 1/(49.50)`
`= 1/1 - 1/2 + 1/2 - 1/3 + ... + 1/49 - 1/50`
`= 1/1 - 1/50`
`= 50/50 - 1/50`
`= 49/50`
`g) 1 - 1/(1.2) - 1/(2.3) - ... - 1/(99.100)`
`= 1 - (1/(1.2) + 1/(2.3) + ... + 1/(99.100))`
`= 1 - (1/1 - 1/2 + 1/2 - 1/3 + ... + 1/99 - 1/100)`
`= 1 - (1/1 - 1/100)`
`= 1 - (100/100 - 1/100)`
`= 1 - 99/100`
`= 100/100 - 99/100`
`= 1/100`
