Consider the system of equations
y= -x^2+9
y=3/x
Find the solution of the system to four demimal places
heck - just set the two equal:
-x^2+9 = 3/x
x^3-9x+3 = 0
cubics usually require a numeric or graphical method. I assume you have studied some of those.
http://www.wolframalpha.com/input/?i=x%5E3-9x%2B3%3D0