We have,
limx→0(e1/x−1e1/x+1)
⇒limx→0⎛⎜ ⎜ ⎜ ⎜⎝e1/x(1−1e1/x)e1/x(1+1e1/x)⎞⎟ ⎟ ⎟ ⎟⎠
⇒limx→0⎛⎜ ⎜ ⎜⎝1−1e1/x1+1e1/x⎞⎟ ⎟ ⎟⎠
⇒1−1e1/01+1e1/0
⇒1−1e∞1+1e∞
⇒1−01+0
⇒1
Hence, this is the answer.