Verifying Solutions for Differential Equations Practice Test

No, because $y'=\dfrac{3}{x^4}$ but $-\dfrac{3}{x}y=-\dfrac{3}{x^4}$.

No, because $y'=-\dfrac{9}{x^4}$ but $-\dfrac{3}{x}y=-\dfrac{3}{x^4}$.

No, because $y'=-\dfrac{1}{x^3}$ but $-\dfrac{3}{x}y=-\dfrac{3}{x^4}$.

Yes, because $y'=-\dfrac{3}{x^4}$ and $-\dfrac{3}{x}y=-\dfrac{3}{x^4}$.

Yes, because $-\dfrac{3}{x}y=-\dfrac{3}{x^3}$ equals $y'$.