№3. а)
= (x-4-2)(x-4+2) = (x-6)(x-2)
б)
= (3x-1-3)(3x-1+3) = (3x-4)(3x+2)
№ 2. а) x²-6x+11 = x²-6x+9+2 = (x-3)²+2
б) x²+6x = x²+6x+9-9= (x+3)²-9
4ˣ -3*2ˣ+2=0
2²ˣ-3*ˣ+2=0
y=2ˣ
y²-3y+2=0
D=3²-4*2=9-8=1
√D=1
y₁=(3-1)/2=1 → 2ˣ=1 → x=0
y₂=(3+1)/2=2 → 2ˣ=2 → x=1
Ответ: х=0 и х=1
X²-x-1=0
D=b²-4ac=-1²-4*1*(-1)=1+4=5
x1=(-b+√D)/2a= (-(-1)+√5)/2= (1+√5)/2
x2=(-b-√D)/2a= (1-√5)/2