(d + 13)*(2*d - 1)
(d + 13)*(2*d - 1*1)
1*(d + 13)*(d - 1/2)
(1*(d + 13))*(d - 1/2)
(13.0 + d)*(-1.0 + 2.0*d)
2 -13 + 2*d + 25*d
-13 + 2*d^2 + 25*d