Simplify square root of 36x4y2

If x is a multiplication symbol, then

square root of 36(4)y^2 = square root of(4^2)(2^2)(y^2) = (4)(2)(y) = 8y

If it is a variable x, then

square root of 36x4y^2 = square root of (4^2)(x)(2^2)(y^2) = (4)(2)(y)(square root of x)= 8y(square root of x)