Question 1055846

Hi! I am stuck haven't done algebra in 35 years.  I am evaluating an equation.  
2x-4y to the 2nd power.  x=3 and y= -2.  I just forget how to start.  Thanks very much
<pre>First, and for your information, this is NOT an equation, but an expression, as it DOESN'T contain an equals sign. 
Second, is it: {{{matrix(1,6, (2x - 4y)^2, or, 2x - 4y^2, or, 2x - (4y)^2, "?")}}}