2 x + 6*x + 5
x^2 + 6*x + 5
(x + 5)*(x + 1)
2 5 + x + 6*x
5 + x^2 + 6*x
(1 + x)*(5 + x)
5.0 + x^2 + 6.0*x
5 + x*(6 + x)