(x-1)x(x+1)=x2 (x-1)x(x+1)=x2 (x²-1)x=x² x³-1x-x²=0 x(x²-x-1)=0 x=0 lub x²-x-1=0 Δ=1+4=5 √Δ=√5 x=(1-√5)/2 lub x=(1+√5)/2 lub x=0