Подстановка условия
[src]-(c - 1)^2 - (c^2 + c - 1)*(c - 1) при c = -1/2
-(c - 1)^2 - (c^2 + c - 1)*(c - 1)
$$- \left(c - 1\right)^{2} - \left(c - 1\right) \left(c^{2} + c - 1\right)$$
-((-1/2) - 1)^2 - ((-1/2)^2 + (-1/2) - 1)*((-1/2) - 1)
$$- \left((-1/2) - 1\right)^{2} - \left((-1/2) - 1\right) \left((-1/2)^{2} + (-1/2) - 1\right)$$
-(-1/2 - 1)^2 - ((-1/2)^2 - 1/2 - 1)*(-1/2 - 1)
$$- \left(-1 - \frac{1}{2}\right)^{2} - \left(-1 - \frac{1}{2}\right) \left(-1 + - \frac{1}{2} + \left(- \frac{1}{2}\right)^{2}\right)$$