please help I can't figure it out

Answer: [tex]\bold{(C)\ \dfrac{x}{4y^2}-\dfrac{5y}{3}-\dfrac{3}{2x}}[/tex]
Step-by-step explanation:
Divide each term in the numerator (top) by the entire denominator (bottom) and cross out their common factor(s).
[tex]\dfrac{3x^2}{12xy^2} = \dfrac{3x(x)}{3x(4y^2)}=\boxed{\dfrac{x}{4y^2}}[/tex]
[tex]\dfrac{20xy^3}{12xy^2} = \dfrac{4xy^2(5y)}{4xy^2(3)}=\boxed{\dfrac{5y}{3}}[/tex]
[tex]\dfrac{18y^2}{12xy^2} = \dfrac{6y^2(3)}{6y^2(2x)}=\boxed{\dfrac{3}{2x}}[/tex]