Answer:
see below
Explanation:
Your spreadsheet or graphing calculator can do this for you.
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If you want to do it by hand, pick a few values for x, compute the corresponding values of f(x), plot those points, and draw a smooth curve through them. You know the horizontal asymptote is y=0, and the whole graph is in the 3rd and 4th quadrants, since the exponential function has been reflected over the x-axis by the leading minus sign.