# Revision history [back]

Not strictly true :

sage: ((2*x+4)/(x^2+1)^2).expand()
2*x/(x^4 + 2*x^2 + 1) + 4/(x^4 + 2*x^2 + 1)


But :

sage: ((2*x+4)/(x^2+1)^2).expand().factor()
2*(x + 2)/(x^2 + 1)^2
sage: ((2*x+4)/(x^2+1)^2).expand().combine()
2*(x + 2)/(x^4 + 2*x^2 + 1)


Note that :

sage: ((2*x+4)/(x^2+1)^2).expand().simplify()
2*x/(x^4 + 2*x^2 + 1) + 4/(x^4 + 2*x^2 + 1)


But that :

sage: ((2*x+4)/(x^2+1)^2).expand().simplify_full()
2*(x + 2)/(x^4 + 2*x^2 + 1)


Sorry.

PS : I fail to see the point...

Not strictly true :

sage: ((2*x+4)/(x^2+1)^2).expand()
2*x/(x^4 + 2*x^2 + 1) + 4/(x^4 + 2*x^2 + 1)


But :

sage: ((2*x+4)/(x^2+1)^2).expand().factor()
2*(x + 2)/(x^2 + 1)^2
sage: ((2*x+4)/(x^2+1)^2).expand().combine()
2*(x + 2)/(x^4 + 2*x^2 + 1)


Note that :

sage: ((2*x+4)/(x^2+1)^2).expand().simplify()
2*x/(x^4 + 2*x^2 + 1) + 4/(x^4 + 2*x^2 + 1)


But that :

sage: ((2*x+4)/(x^2+1)^2).expand().simplify_full()
2*(x + 2)/(x^4 + 2*x^2 + 1)


Sorry.

This is general :

sage: var("a")
a
sage: a*(2*x+4)
2*a*(x + 2)


PS : I fail to see the point...