A) -4y(y+2)+(y-5)^2 =
= -4y^2-8y+y^2-10y+25 = -3y^2-18y+25
B) 2(a-3)^2-2a^2 =
=2(a^2-6a+9)-2a^2 = 2a^2-12a+18-2a^2 = -12a+18
X³+2x²+x=0
x(x²+2x+1)=0
x(x+1)²=0
x1=0, x2=-1
(a+b)²=(a+b)(a+b)=a²+2ab+b²
(x+1)²=0⇔x+1=0⇒x=-1
3(х-7)+4=7х-1
-4х-16=0
4х=-16
х=-4
X^3 + X^2 = 9X + 9
X^2 * ( X + 1 ) = 9 * ( X + 1)
( X^2 - 9 ) * ( X + 1 ) = 0
X^2 - 9 = 0 ---> X^2 = 9 ---> X1 = + 3 ; X 2 = ( - 3 )
X + 1 = 0 ---> X + ( - 1 )
Ответ: ( - 1 ) ; ( - 3 ) ; + 3