Это
х2-6х-8-(х2-4х-3)=-2х-5=1 целая 1/2
5x - 5y + ( X - y )^2 = 5 * ( X - y ) + ( X - y )^2 = ( X - y )*( 5 + X - y )
An=a1+d(n-1)
14=10+4(n-1)
14-10=4n-4
4+4=4n
4n=8
n=2
Sn=(a1+an)/2 *n
Sn=(10+14)/2 *2=24
D = 1 +24 = 25 = 5²
x1 = 1
x2 = - 1,5
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