Find the equation of the tangent to the curve y=2-e^-x at the point where x=1.

Can someone please do this step by step and explain?

Point of contact :

when x=1 , y = 2 - e^-1 = 2 - 1/e
= (2e-1)/e

dy/dx = e^-x
so when x=1 , slope = e^-1 = 1/e

using y = mx + b
(2e-1)/e = (1/e)(1) + b
b = (1-e)/e

so y = (1/e)x + (1-e)/e