3x^4y^2/xy^2 --> let's make this easier on the eyes:
[(3x^4)(y^2)] / [x(y^2)] --> there is one x on the bottom (denominator), and that will cancel out one of the 4 x's on the too (numerator):
[(3x^3)(y^2)] / (y^2) --> the 2 y's on the bottom (y^2) will cancel out the y^2 on the top, so we are left with: 3x^3 as the final, simplified answer