function division

edit

I plotted the 2 following equations: (2x^3+2x) / (x^2+1) 2*x

p1 = plot((2*x^3+2*x) / (x^2+1), (x,-15,15), ymin=-15, ymax=15)
p2 = plot(2*x, (x,-15,15), ymin=-15, ymax=15, color='red') 
p0= p1+p2
show(p0)

And they both displayed the same output: I tried to do, (2x^3+2x) / (x^2+1) , but was displayed, 2*(x^3 + x)/(x^2 + 1)

How can I get 2*x to be displayed as the output?