Question

Докажите тождество
(7 х - 3 ) (4-8х ) +2х( 28х - 26 ) = -12
(1.1X^2)(X^2)-10)-x(1.1X^3-9X)= -2X^2
( -y^3 + 5y ) 2y - 10y^2 (1+0.2y^2)= - 4y^4
(2.5a + b^2 ) (-4a) + 2a(5a-b^2)=-6ab^2