2545.sagews

var('u,v')
p=parametric_plot3d( (u,v,2*u+3*v),(u,-3,3),(v,-3,3),color='red')
q=parametric_plot3d( (u,v,2.3*u+3.3*v),(u,-3,3),(v,-3,3))
p+q

var('u,v')
p=parametric_plot3d( (u,v,2*u+3*v),(u,-3,3),(v,-3,3),color='red',plot_points=200)
q=parametric_plot3d( (u,v,2.3*u+3.3*v),(u,-3,3),(v,-3,3),plot_points=200)
p+q