Which of the following integrals is equivalent to ∫3xx2+4dx\int \frac{3x}{x^2+4} dx∫x2+43xdx using the substitution u=x2+4u = x^2+4u=x2+4?
32∫1udu\frac{3}{2} \int \frac{1}{u} du23∫u1du
3∫1udu3 \int \frac{1}{u} du3∫u1du
32∫udu\frac{3}{2} \int u du23∫udu
3∫udu3 \int u du3∫udu