2 (2 + c) - c*(c - 4)
(2 + c)^2 - c*(c - 1*4)
4 + 8*c
1*(c + 1/2)
4.0*(1 + 0.5*c)^2 - c*(-4.0 + c)
2 2 (2 + c) - c + 4*c
(2 + c)^2 - c^2 + 4*c