What you are asking are the "roots" of the equation x2 = 3x. Remember that the equation that will allow us to get the root/s is the quadratic equation given by ax2 + bx + c = 0.
In this case, you need to rewrite the equation from x2 = 3x by moving all terms to the left. This will then give you the form x2 -3x = 0, which will allow us to identify a, b and c of the quadratic equation.
a = 1
b = -3
c = 0
We now substitute this to the quadratic formula:
Substituting the values will give you this:
x= [3+3]/2 = 6/2 = 3
x= [3-3]/2 = 0
Hence, the values of x or the roots of the equation are 3 and 0.