x(x+3) = (3x-1)^2+3
x²+3x=9x²-6x+1+3
x²+3x-9x²+6x-1-3=0
-8x²+9x-4=0
Δ=81-4*(-8)*(-4)=81*32*(-4)=-10368
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-2x^2-5 = 0
Δ-4*(-2)*(-5)=-40
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(2x+3)^2 = (x+3)^2
4x²+12x+9=x²+6x+9
4x²+12x+9-x²-6x-9=0
3x²+6x=0
Δ=-4*3*6=-72
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x^2+6x+5 = 0
Δ=36-4*1*5=36-20=16
√Δ=4
x1=-6-4 przez 2=-10/2=-5
x2=-6+4 przez 2=-2/2=-1
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(x-4)x = -4
x²-4x+4=0
Δ=16-4*1*4=16-16=0
x0=-b/2a=4/2=2