Решите уравнения, используя замену неизвестного. (x2-x)^2 - 3(x2-x)+2=0 (x2-10x)^2+8(x-5)^2-209=0

(х^2 - х )^2 - 3( х^2 - х ) + 2 = 0 х^2 - х = а а^2 - 3а + 2 = 0 d = 9 - 8 = 1 a1 = ( 3 + 1 ) : 2 = 2 a2 = ( 3 - 1 ) : 2 = 1 x^2 - x = a x^2 - x = 2 x^2 - x - 2 = 0 d = 1 + 8 = 9 = 3^2 x1 = ( 1 + 3 ) : 2 = 2 x2 = ( 1 - 3 ) : 2 = - 1 x^2 - x - 1 = 0 d = 1 + 4 = 5 = ( v 5 )^2 х1 = ( 1 + v5 ) : 2 = 0,5 + 0,5v5 x2 = 0,5 - 0,5v5 ответ 2 ; - 1 ; ( 0,5 + 0,5v5 ) ; ( 0,5 - 0,5v5 ) ========== ( x^2 - 10x )^2 + 8( x - 5 )^2 - 209 = 0 ( x - 5 )^2 = x^2 - 10x + 25 x^2 - 10x = a x^2 - 10x + 25 = a + 25 a^2 + 8( a + 25 ) - 209 = 0 a^2 + 8a + 200 - 209 = 0 a^2 + 8a - 9 = 0 d = 64 + 36 = 100 = 10^2 a1 = ( - 8 + 10 ) : 2 = 1 a2 = ( - 8 - 10 ) : 2 = - 9 x^2 - 10x = 1 x^2 - 10x - 1 = 0 d = 100 + 4 = 104 = ( v100•1,04 )^2 = ( 10v1,04)^2 x1 = ( 10 + 10v1,04 ) : 2 = 5 + 5v1,04 x2 = 5 - 5v1,04 x^2 - 10x = - 9 x^2 - 10x + 9 = 0 d = 100 - 36 = 64 = 8^2 x1 = ( 10 + 8 ) : 2 = 9 x2 = ( 10 - 8 ) : 2 = 1 ответ 9 ; 1 ; ( 5 + 5v1,04 ) ; ( 5 - 5v1,04 )

Формула - s=2(ab + bc + ac) 2(3х5+5х6+6х3) 2(15+30+18) 2х63=126.