1: x = x: 81 what number can replace x?

Multiply 1/x = x/81 by 81x and you get

... 81 = x²

Taking the square root gives

... x = ±9

Either 9 or -9 can replace X to make the proportion statement true.

the final function for the graph becomes x-2=-1. before graphing you solve the equation, where x=1. then graph accordingly.   ( on the x-axis, 1 on the line will possess a vertical line.)