Б) 2(y-1) -(1 -y)² =0
2y-2 -(1 -2y +y²) =0
2y -2 -1 +2y -y² =0
4y -3 -y² =0 *(-1)
y² -4y +3 =0
D=b² -4ac(a=1,b= -4,c=3)
D=16 -12 =4 =2²
x1,x2=(-b+-корень изD)/2a
x1 =(4 -2)/2 =1
x2 =(4 +2)/2 =3
г) (y -3)² -4(3 -y) =0
y² -6y +9 -12 +4y =0
y² -2y -3 =0
(a=1, b= -2, c= -3)
D=4 +12 =16 =4²
x1 =(2 -4)/2 = -1
x2 =(2 +4)/2 =3