2x^2+5sqrt(x-2)-8=0 completes the equation so that at x=2 the equation is satisfied. Rounding to the nearest thousand or thousandth isn't necessary for this solution, since it's exact. If the constant 8 is increased, there may be more than one solution for x. For example, 2x^2+5sqrt(x-2)=23 or 2x^2+5sqrt(x-2)-23=0 has two solutions, one of which is 3. The other is irrational, 3.8614, and so would be rounded off to 3.861. (There are two solutions if sqrt delivers a positive or negative result, for example, sqrt(1) is -1 or +1.)