In each of the following, determine whether the given values are solutions of the given equation or not: `x^2-3x+2=0,\ \ x=2,\ x=-1` (ii) `x^2+x+1=0,\ \ x=0,\ x=1` (iii) `x^2-3sqrt(3)x+6=0,\ \ x=sqrt(3),\ \ x=-2sqrt(3)` (iv) `x+1/x=(13)/6,\ \ x=5/6,\ \ x=4/3`