Question 1125476
your equation is 18 * (x-2) = 1 + (20 / (x + 2))


multiply both sides of this equation by (x + 2) to get:


18 * (x-2) * (x+2) = (x + 2) + 20


(x-2) * (x+2) is equal to (x^2 - 4)


equation becomes:


18 * (x^2 - 4) = (x + 2) + 20


simplify to get 18 * x^2 - 72 = x + 22


subtract x + 22 from both sides of the equation to get:


x^2 - 72 - x - 22 = 0


combine like terms to get:


x^2 - x - 94 = 0


factor this quadratic equation to get:


x = 2.313164797 or x = -2.257609241


that's your solution.


you can show that this is true graphically as shown below:


<img src = "http://theo.x10hosting.com/2018/100704.jpg" alt="$$$" >


the red line is 18 * (x - 2).


the blue line is 1 + (20 / (x + 2)).


the solution is the intersection of those two lines.


x = 2.313164797 or x = -2.257609241 rounds to x = 2.313 or x = -2.258 as shown on the graph.