show whether the sets A={3,3,2}, B={3,2,2,3} and C={x:x^2-5x+6=0} are equal.

A={3,3,2}, B={3,2,2,3}

are not proper definitions of sets, because they are not supposed to contain duplicate elements. Assuming a correct definition of A and B containing the given elements, then they are:
A={2,3}, and B={2,3}
For C, the two solutions to the given quadratic equations are 2 and 3, so
C={x:x^2-5x+6=0}
={x:(x-2)(x-3)=0}
= {2,3}

What would you propose for the answer?