2x - ay + bz
a = 3c
b = 14c^3
x = 5c^3 + 2
y = 6c^2 - c + 13
z = 5c - 1
2(5c^3 + 2) - 3c*(6c^2 - c + 13) + 14c^3*(5c - 1) =
= 10c^3 + 4 - 3c*6c^2 + 3c*c - 39c + 70c^4 - 14c^3 =
= 10c^3 + 4 - 18c^3 + 3c^2 - 39c + 70c^4 - 14c^3 =
= 70c^4 - 22c^3 + 3c^2 - 39c + 4
{x-6y=17 , => x=17+6y х=17+6(-2)=5
{5x+6у=13 так как х=17+6у
5(17+6у)+6у=13
85+36у=13
у=-2
1. 97 градусов
2. 82 и 47 градуса
3. 20 и 70 градусов