2. v) 1/4=0.25
0.25x²-x+1=0
D=b²-4ac(a=0.25,b=-1,c=1)
D=1-1=0, при D=0
x1,x2=(-b+-0)/2a
x1=1/0.5=2. x2=-2
ответ: х=2
3.
(3x(x+1)+4(x-1))/(x-1)(x+1)=
=6/(x²-1)
(3x²+3+4x-4)/(x²-1)=6/(x²-1)
(3x²+4x-1-6)/(x²-1)=0
3x²+4x-7=0
D=16+84=100=10²
x1,x2=(-b+-корень изD)/2a
x1=(-4-10)/6=-14/6=-2 2/6=
=-2 1/3
x2=(-4+10)/6=1