Подстановка условия
[src]13*(a - 2) + 2*(a + 1) при a = 1/4
$$13 \left(a - 2\right) + 2 \left(a + 1\right)$$
13*((1/4) - 2) + 2*((1/4) + 1)
$$13 \left((1/4) - 2\right) + 2 \left((1/4) + 1\right)$$
13*(1/4 - 2) + 2*(1/4 + 1)
$$13 \left(-2 + \frac{1}{4}\right) + 2 \left(\frac{1}{4} + 1\right)$$