[quote=LegendBegins]
Uh... you know that all of these methods give you exact results if you actually do them correctly, right?
[/quote]

I never said they didn't. When I said least reliable I meant that a lot of the time it's a lot more complicated than the other methods. With graphing, obviously the answer is exact, but you have to estimate exactly what point the graph is on. What if the answer is (5.89264, 8.9999826)? Estimation would be incredibly hard with that, and the trial and error time required would be rather annoying if you weren't able to use your calculator really fast. I find substitution the fastest method.